Math & Dyscalculia

Resources

Amalric, M., & Dehaene, S. (2016). Origins of the brain networks for advanced mathematics in expert mathematicians. Proceedings of the National Academy of Sciences, 113(18), 4909-4917. https://doi.org/10.1073/pnas.1603205113

Ang, D., Sun, B., & Cheung, P. (2024). The effect of book genre in eliciting teacher math talk. Mind, Brain, and Education. https://doi.org/10.1111/mbe.12433

Ansari, D., Price, G., & Holloway, I. (2010). Typical and atypical development of basic numerical magnitude representations: A review of behavioral and neuroimaging studies. In The developmental relations among mind, brain and education (pp. 105-127). Springer, Dordrecht.

Ansari, D. (2008). Effects of development and enculturation on number representation in the brain. Nature Reviews Neuroscience, 9(4), 278-291. https://doi.org/10.1038/nrn2334

Archibald, L., Cardy, J.O., Joanisse, M.F., & Ansari, D. (2013). Language, reading, and math learning profiles in an epidemiological sample of school age children. PLoS ONE 8(10), 77463. https://doi.org/10.1371/journal.pone.0077463

Arsalidou, M., Pawliw-Levac, M., Sadeghi, M., & Pascual-Leone, J. (2018). Brain areas associated with numbers and calculations in children: Meta-analyses of fMRI studies. Developmental Cognitive Neuroscience, 30, 239-250. https://doi.org/10.1016/j.dcn.2017.08.002

Ashkenazi, S., Rubinsten, O., & De Smedt, B. (2017). Associations between reading and mathematics: Genetic, brain imaging, cognitive and educational perspectives. Frontiers in Psychology, 8, 600. https://doi.org/10.3389/fpsyg.2017.00600

Bartelet, D., Ansari, D., Vaessen, A. & Blomert, L. (2014). Cognitive subtypes of mathematics learning difficulties in primary education. Research in Developmental Disabilities, 35, 657-670. https://doi.org/10.1016/j.ridd.2013.12.010

Bartelet, D., Vaessen, A. & Blomert, L. & Ansari, D. (2014). What basic number processing measures in kindergarten explain unique variability in grade 1 arithmetic proficiency? Journal of Experimental Child Psychology, 117C, 12-28. https://doi.org/10.1016/j.jecp.2013.08.010

Bates, K. E., Gilligan‐Lee, K., & Farran, E. K. (2021). Reimagining mathematics: The role of mental imagery in explaining mathematical calculation skills in childhood. Mind, Brain, and Education, 15(2), 189-198. https://doi.org/10.1111/mbe.12281

Bernabini, L., Tobia, V., & Bonifacci, P. (2021). Intergenerational features of math skills: Symbolic and non-symbolic magnitude comparison and written calculation in mothers and children. Journal of Cognition and Development, 22(1), 149-167. https://doi.org/10.1080/15248372.2020.1844711

Black, L., Choudry, S., Pickard-Smith, K., & Williams, J. (2019). Theorising the place of emotion–cognition in research on mathematical identities: the case of early years mathematics. ZDM, 1-11. https://doi.org/10.1007/s11858-018-01021-9

Bonny, J. W., & Lourenco, S. F. (2013). The approximate number system and its relation to early math achievement: Evidence from the preschool years. Journal of Experimental Child Psychology, 114(3), 375-388. https://doi.org/10.1016/j.jecp.2012.09.015

Bugden, S., & Ansari, D. (2015). Probing the nature of deficits in the ‘Approximate Number System’ in children with persistent Developmental Dyscalculia. Developmental Science, 19(5), 817-833. https://doi.org/10.1111/desc.12324

Bugden, S., Peters, L., Nosworthy, N., Archibald, L., & Ansari, D. (2021). Identifying children with persistent developmental dyscalculia from a 2‐min test of symbolic and nonsymbolic numerical magnitude processing. Mind, Brain, and Education, 15(1), 88-102. https://doi.org/10.1111/mbe.12268

Butterworth, B., Varma, S., & Laurillard, D. (2011). Dyscalculia: From brain to education. Science, 332(6033), 1049-1053. https://doi.org/10.1126/science.1201536

Callaway, E. (2013). Dyscalculia: Number games. Nature. 493, 150-153. https://doi.org/10.1038/493150a

Cantlon, J. F. (2012). Math, monkeys, and the developing brain. Proceedings of the National Academy of Sciences, 109 (Supplement 1), 10725-10732.

Carey, E., Hill, F., Devine, A., & Szücs, D. (2016). The chicken or the egg? The direction of the relationship between mathematics anxiety and mathematics performance. Frontiers in Psychology, 6, 1987. https://doi.org/10.3389/fpsyg.2015.01987

Clements, D. H., Sarama, J., & Germeroth, C. (2016). Learning executive function and early mathematics: Directions of causal relations. Early Childhood Research Quarterly, 36, 79-90. https://doi.org/10.1016/j.ecresq.2015.12.009

Cohen, L. D., & Rubinsten, O. (2021). The complex pathways toward the development of math anxiety and links with achievements. Heterogeneous Contributions to Numerical Cognition, 311-326. https://doi.org/10.1016/B978-0-12-817414-2.00003-8

Collins, S. E., Thompson, D. K., Kelly, C. E., Yang, J. Y., Pascoe, L., Inder, T. E., ... & Anderson, P. J. (2021). Development of brain white matter and math computation ability in children born very preterm and full-term. Developmental Cognitive Neuroscience, 51, Article 100987. https://doi.org/10.1016/j.dcn.2021.100987

Crawford, A. (2007). Learning to teach science as inquiry in the rough and tumble of practice. Journal of Research in Science Teaching, 44(4), 613–642. https://doi.org/10.1002/tea.20157

Daker, R. J., Gattas, S. U., Sokolowski, H. M., Green, A. E., & Lyons, I. M. (2021). First-year students’ math anxiety predicts STEM avoidance and underperformance throughout university, independently of math ability. npj Science of Learning, 6(1), 1-13. https://doi.org/10.1038/s41539-021-00095-7

Dastjerdi, M., Ozker, M., Foster, B. L., Rangarajan, V., & Parvizi, J. (2013). Numerical processing in the human parietal cortex during experimental and natural conditions. Nature Communications, 4. https://doi.org/10.1038/ncomms3528

Dehaene, S., Piazza, M., Pinel, P., and Cohen, L. (2003). Three parietal circuits for number processing. Cognitive Neuropsychology, 20, 487-506. https://doi.org/10.1080/02643290244000239

Dehaene, S. (2011). The number sense: How the mind creates mathematics (Rev. and updated ed.). Oxford University Press.

Dehaene, S., Izard, V., Spelke, E., & Pica, P. (2008). Log or linear? Distinct intuitions of the number scale in Western and Amazonian indigene cultures. Science, 320(5880), 1217-1220. https://doi.org/10.1126/science.1156540

Dennis, M., & Barnes, M. (2002). Math and numeracy in young adults with spina bifida and hydrocephalus. Developmental Neuropsychology, 21(2), 141-155. https://doi.org/10.1207/S15326942DN2102_2

De Smedt, B., Ansari, D., Grabner, R. H., Hannula, M. M. Schneider, M., & Verschaffel, L. (2010). Cognitive neuroscience meets mathematics education: It takes two to tango. Educational Research Review, 5(1), 97–105. http://dx.doi.org/10.1016/j.edurev.2011.10.002

Devlin, K. (2010). The mathematical brain. In D. A. Souza (Ed.), Mind, brain and education: Neuroscience implications for the classroom (pp.163-178). Solution Tree Press.

de Vries, H. G., Polk, K. D., & Missall, K. N. (2021). Math talk during traditional and digital number board game play. Journal of Applied Developmental Psychology, 76, Article 101312. https://doi.org/10.1016/j.appdev.2021.101312

Dowker, A., Sarkar, A., & Looi, C. Y. (2016). Mathematics anxiety: What have we learned in 60 years? Frontiers in Psychology, 7, 508. https://doi.org/10.3389/fpsyg.2016.00508

Egorova, A., Ngo, V., Liu, A. S., Mahoney, M., Moy, J., & Ottmar, E. (2024). Mathematics presentation matters: How superfluous brackets and higher‐order operator position in mathematics can impact arithmetic performance. Mind, Brain, and Education, 18(3), 258-269.  https://doi.org/10.1111/mbe.12421

Evans, T. M., Kochalka, J., Ngoon, T. J., Wu, S. S., Qin, S., Battista, C., & Menon, V. (2015). Brain structural integrity and intrinsic functional connectivity forecast 6 year longitudinal growth in children's numerical abilities. The Journal of Neuroscience, 35(33), 11743-11750. https://doi.org/10.1523/JNEUROSCI.0216-15.2015

Feigenson, L., Dehaene, S., & Spelke, E. (2004). Core systems of number. Trends in Cognitive Sciences, 8(7), 307-314. http://dx.doi.org/10.1016/j.tics.2004.05.002

Gromov, M. (2017). Math currents in the brain. In Simplicity: Ideals of practice in mathematics and the arts (pp. 105-118). Springer, Cham.

Guberman, R., Grobgeld, E., Rozanov, Y. M., & Eraky, A. (2022). Is the bridge really so far away? Elementary mathematics teachers' competencies to implement neuroscience theory into their teaching practices. International Journal of Innovation in Science and Mathematics Education, 30(1).

Halberda, J., Mazzocco, M. M., & Feigenson, L. (2008). Individual differences in non-verbal number acuity correlate with maths achievement. Nature, 455(7213), 665-668. https://doi.org/10.1038/nature07246

Hawes, Z., Merkley, R., Stager, C. L., & Ansari, D. (2021). Integrating numerical cognition research and mathematics education to strengthen the teaching and learning of early number. British Journal of Educational Psychology, 91(4), 1073-1109. https://doi.org/10.1111/bjep.12421

Hiebert, J., Stigler, J. W., Jacobs, J. K., Givvin, K. B., Garnier, H., Smith, M., Hollingsworth, H., Manaster, A., Wearne, D., & Gallimore, R. (2005). Mathematics teaching in the United States today (and tomorrow): Results from the TIMSS 1999 video study. Educational Evaluation and Policy Analysis, 27(2), 111–132.

Hyde, D. C., & Ansari, D. (2018). Advances in understanding the development of the mathematical brain. Developmental Cognitive Neuroscience, 30, 236-238. https://doi.org/10.1016/j.dcn.2018.04.006

Iuculano, T., Rosenberg-Lee, M., Richardson, J., Tenison, C., Fuchs, L., Supekar, K., & Menon, V. (2015). Cognitive tutoring induces widespread neuroplasticity and remediates brain function in children with mathematical learning disabilities. Nature Communications, 6, 8453. https://doi.org/10.1038/ncomms9453

Jacob, S. N., Vallentin, D., & Nieder, A. (2012). Relating magnitudes: the brain's code for proportions. Trends in Cognitive Sciences, 16(3), 157-166. http://dx.doi.org/10.1016/j.tics.2012.02.002

Jirout, J. J., Holmes, C. A., Ramsook, K. A., & Newcombe, N. S. (2018). Scaling up spatial development: A closer look at children's scaling ability and its relation to number knowledge. Mind, Brain, and Education. https://doi.org/10.1111/mbe.12182

Johnstone, A. H. (1991). Why is science difficult to learn? Things are seldom what they seem. Journal of Computer Assisted Learning, 7(2), 75–83.

Jones, W. J., Childers, T. L., & Jiang, Y. (2012). The shopping brain: Math anxiety modulates brain responses to buying decisions. Biological Psychology, 89(1), 201-213. https://doi.org/10.1016/j.biopsycho.2011.10.011

Jonsson, B., Liljekvist, Y., & Norqvist, M. (2015). Learning mathematics without a suggested solution method: Durable effects on performance and brain activity. University of Pennsylvania. https://doi.org/10.1016/j.tine.2015.03.002

Kang, N.-H. (2008). Learning to teach science: Personal epistemologies, teaching goals, and practices of teaching. Teaching and Teacher Education, 24(2), 478–498. https://doi.org/10.1016/j.tate.2007.01.002

Kaufmann, L., Vogel, S. E., Starke, M., Kremser, C., Schocke, M., & Wood, G. (2009). Developmental dyscalculia: Compensatory mechanisms in left intraparietal regions in response to nonsymbolic magnitudes. Behavioral and Brain Functions, 5(1), 1. https://doi.org/10.1186/1744-9081-5-35

Kucian, K., & von Aster, M. (2015). Developmental dyscalculia. European Journal of Pediatrics, 174(1), 1-13. https://doi.org/10.1007/s00431-014-2455-7

Laurens, T., Batlolona, F. A., Batlolona, J. R., & Leasa, M. (2018). How does realistic mathematics education (RME) improve students’ mathematics cognitive achievement. Eurasia Journal of Mathematics, Science and Technology Education, 14(2), 569-578. https://doi.org/10.12973/ejmste/76959

Lebel, C., Rasmussen, C., Wyper, K., Andrew, G., & Beaulieu, C. (2010). Brain microstructure is related to math ability in children with fetal alcohol spectrum disorder. Alcoholism: Clinical and Experimental Research, 34(2), 354-363. https://doi.org/10.1111/j.1530-0277.2009.01097.x

Lee, J., Lee, H. J., Song, J., & Bong, M. (2021). Enhancing children's math motivation with a joint intervention on mindset and gender stereotypes. Learning and Instruction, 73, Article 101416. https://doi.org/10.1016/j.learninstruc.2020.101416

Leibovich, T., Vogel, S. E., Henik, A., & Ansari, D. (2015). Asymmetric processing of numerical and nonnumerical magnitudes in the brain: An fMRI study. Journal of Cognitive Neuroscience, 28(1),1-11. https://doi.org/10.1162/jocn_a_00887

Leikin, R. (2018). How can cognitive neuroscience contribute to mathematics education? Bridging the two research areas. In Invited Lectures from the 13th International Congress on Mathematical Education (pp. 363-383). Springer, Cham.

Lowery, N. V. (2002). Construction of teacher knowledge in context: Preparing elementary teachers to teach mathematics and science. School Science and Mathematics, 102(2), 68–83. https://doi.org/10.1111/j.1949-8594.2002.tb17896.x

Lyons, I.M., Ansari, D. & Beilock, S.L. (2015). Qualitatively different coding of symbolic and nonsymbolic numbers in the human brain. Human Brain Mapping, 26, 475-488. https://doi.org/10.1002/hbm.22641

Lyons, I.M. & Ansari, D. (2015). Numerical order processing in children: From reversing the distance-effect to predicting arithmetic. Mind, Brain and Education, 9, 207-21. https://doi.org/10.1111/mbe.12094

Lyons, I.M., Price, G.R., Vaessen, A., Blomert, L. & Ansari, D. (2014). Numerical predictors of arithmetic success in grades 1-6. Developmental Science, 17, 714-26. https://doi.org/10.1111/desc.12152

Mammarella, I. C., Hill, F., Devine, A., Caviola, S., & Szűcs, D. (2015). Math anxiety and developmental dyscalculia: A study on working memory processes. Journal of Clinical and Experimental Neuropsychology, 37(8), 878-887. https://doi.org/10.1080/13803395.2015.1066759

Mareschal, D. (2016). The neuroscience of conceptual learning in science and mathematics. Current Opinion in Behavioral Sciences, 10, 114-118.

Matejko, A. & Ansari, D. (2015) Drawing connections between white matter and numerical and mathematical cognition: A literature review. Neuroscience & Biobehavioral Reviews, 48C, 35-52. https://doi.org/10.1016/j.neubiorev.2014.11.006

Metu, C., Marbán, J. M., & Espina, E. (2025). Growth mindset in mathematics: A bibliometric analysis. JRAMathEdu (Journal of Research and Advances in Mathematics Education), 1-14. https://doi.org/10.23917/jramathedu.v10i1.6482

Millar, R. (1991). Why is science hard to learn? Journal of Computer Associated Learning, 7(2), 66–74. https://doi.org/10.1111/j.1365-2729.1991.tb00229.x

Miranda, L. (2010). On trends and rhythms in scientific and technological knowledge evolution: A quantitative analysis. International Journal of Technology Intelligence and Planning, 6(1), 76–109.

Moeller, K., Willmes, K., & Klein, E. (2015). A review on functional and structural brain connectivity in numerical cognition. Frontiers in Human Neuroscience, 9. https://doi.org/10.3389/fnhum.2015.00227

Namazi, H. (2018). Can we mathematically correlate brain memory and complexity. ARC Journal of, 216, 1-3. http://dx.doi.org/10.20431/2456-057X.0302003

Nieder, A., & Dehaene, S. (2009). Representation of number in the brain. Annual Review of Neuroscience, 32, 185-208. https://doi.org/10.1146/annurev.neuro.051508.135550

O'Boyle, M. W., Cunnington, R., Silk, T. J., Vaughan, D., Jackson, G., Syngeniotis, A., & Egan, G. F. (2005). Mathematically gifted male adolescents activate a unique brain network during mental rotation. Cognitive Brain Research, 25(2), 583-587. https://doi.org/10.1016/j.cogbrainres.2005.08.004

Papic, M. M., & Papic, C. (2025). Is confidence in mathematics pedagogy enough? Exploring early childhood teachers’ mathematics beliefs and confidence. Early Childhood Education Journal, 1-17. https://doi.org/10.1007/s10643-024-01840-4

Peters, S., Van der Meulen, M., Zanolie, K., & Crone, E. A. (2017). Predicting reading and mathematics from neural activity for feedback learning. Developmental Psychology, 53(1), 149. https://doi.org/doi:10.1037/dev0000234

Peters, L., & De Smedt, B. (2018). Arithmetic in the developing brain: A review of brain imaging studies. Developmental Cognitive Neuroscience, 30, 265-279. https://doi.org/10.1016/j.dcn.2017.05.002

Piazza, M., Facoetti, A., Trussardi, A. N., Berteletti, I., Conte, S., Lucangeli, D., Dehaene, S., & Zorzi, M. (2010). Developmental trajectory of number acuity reveals a severe impairment in developmental dyscalculia. Cognition, 116(1), 33-41. http://dx.doi.org/10.1016/j.cognition.2010.03.012

Prescott, J., Gavrilescu, M., Cunnington, R., O'Boyle, M. W., & Egan, G. F. (2010). Enhanced brain connectivity in math-gifted adolescents: An fMRI study using mental rotation. Cognitive Neuroscience, 1(4), 277-288.

Price, G. R., Mazzocco, M. M., & Ansari, D. (2013). Why mental arithmetic counts: Brain activation during single digit arithmetic predicts high school math scores. The Journal of Neuroscience, 33(1), 156-163. https://doi.org/10.1523/JNEUROSCI.2936-12.2013

Rubinsten, O. (2015). Link between cognitive neuroscience and education: The case of clinical assessment of developmental dyscalculia. Frontiers in Human Neuroscience, 9, 304. https://doi.org/10.3389/fnhum.2015.00304

Ryve, A. (2011). Discourse research in mathematics education: A critical evaluation of 108 journal articles. Journal of Research in Mathematics Education, 42(2), 167–199. https://doi.org/10.5951/jresematheduc.42.2.0167

Soylu, A. (2024). Going beyond the cognitivist

Spelke, E. S. (2017). Core knowledge, language, and number. Language Learning and Development, 13(2), 147-170. https://doi.org/10.1080/15475441.2016.1263572

Starr, A., Libertus, M. E., & Brannon, E. M. (2013). Number sense in infancy predicts mathematical abilities in childhood. Proceedings of the National Academy of Sciences, 110(45), 18116-18120. https://doi.org/10.1073/pnas.1302751110

Steele, J. R., & Ambady, N. (2006). “Math is hard!” The effect of gender priming on women’s attitudes. Journal of Experimental Social Psychology, 42(4), 428–436. https://doi.org/10.1016/j.jesp.2005.06.003

Suárez-Pellicioni, M., Núñez-Peña, M. I., & Colomé, À. (2013). Abnormal error monitoring in math-anxious individuals: Evidence from error-related brain potentials. PloS one, 8(11), Article e81143. https://doi.org/10.1371/journal.pone.0081143

Supekar, K., Iuculano, T., Chen, L., & Menon, V. (2015). Remediation of childhood math anxiety and associated neural circuits through cognitive tutoring. The Journal of Neuroscience, 35(36), 12574-12583. https://doi.org/10.1523/JNEUROSCI.0786-15.2015

Supekar, K., Swigart, A. G., Tenison, C., Jolles, D. D., Rosenberg-Lee, M., Fuchs, L., & Menon, V. (2013). Neural predictors of individual differences in response to math tutoring in primary-grade school children. Proceedings of the National Academy of Sciences, 110(20), 8230-8235. https://doi.org/10.1073/pnas.1222154110

Szkudlarek, E., & Brannon, E. M. (2017). Does the approximate number system serve as a foundation for symbolic mathematics?. Language Learning and Development, 13(2), 171-190. https://doi.org/10.1080/15475441.2016.1263573

Szűcs, D., & Goswami, U. (2013). Developmental dyscalculia: Fresh perspectives. Trends in Neuroscience and Education, 2(2), 33-37. https://doi.org/10.1016/j.tine.2013.06.004

University of Western Ontario. (2016). Numerical cognition lab [website]. http://www.numericalcognition.org/

Vogel, S. E., & De Smedt, B. (2021). Developmental brain dynamics of numerical and arithmetic abilities. npj Science of Learning, 6(1), 1-11. https://doi.org/10.1038/s41539-021-00099-3

Wang, T. H., & Kao, C. H. (2024). Pupil dilation as an index of examinee's cognitive load in answering a mathematics question: A comparison study of different approaches. Mind, Brain, and Education, 18(1), 43-47.  https://doi.org/10.1111/mbe.12388

Wang, C., Ren, T., Zhang, X., Dou, W., Jia, X., & Li, B. M. (2022). The longitudinal development of large‐scale functional brain networks for arithmetic ability from childhood to adolescence. European Journal of Neuroscience, 55(7), 1825-1839. https://doi.org/10.1111/ejn.15651

Weed, K., Usry, C. H., & Stafford, J. (2021). College students who are mindful about math achieve better grades. Mind, Brain, and Education. https://doi.org/10.1111/mbe.12308

Williams, J. (2011). Looking back, looking forward: Valuing post-compulsory mathematics education. Research in Mathematics Education, 13(2), 213–222. https://doi.org/10.1080/14794802.2011.585831

Wirebring, L. K., Lithner, J., Jonsson, B., Liljekvist, Y., Norqvist, M., & Nyberg, L. (2015). Learning mathematics without a suggested solution method: Durable effects on performance and brain activity. Trends in Neuroscience and Education, 4(1-2), 6-14. https://doi.org/10.1016/j.tine.2015.03.002

Yanowitz, K. L. (2010). Using analogies to improve elementary school students’ inferential reasoning about scientific concepts. School Science and Mathematics, 101(3), 133–142. https://doi.org/10.1111/j.1949-8594.2001.tb18016.x

Young, C. B., Wu, S. S., & Menon, V. (2012). The neurodevelopmental basis of math anxiety. Psychological Science, Article 0956797611429134. https://doi.org/10.1177%2F0956797611429134

Zacharopoulos, G., Sella, F., & Kadosh, R. C. (2021). The impact of a lack of mathematical education on brain development and future attainment. Proceedings of the National Academy of Sciences, 118(24). https://doi.org/10.1073/pnas.2013155118

Other Resources

Bugden, S. & Ansari, D. (2014). When your brain can’t do 2+2: A case of developmental dyscalculia. Young Minds, 2(8). https://doi.org/10.3389/frym.2014.00008

Butterworth, B. (2012, July 24). Dyscalculia - Numberphile [Video]. YouTube. https://www.youtube.com/watch?v=p_Hqdqe84Uc&list=PL60hj6d9o_BaLC3TZ_lar8gGTqbqk5lNR

Dyslexic Advantage. (2013, July 20). Neurobiology of learning disorders - Dyslexia ADHD Dyscalculia Dysgraphia [Video]. YouTube. https://www.youtube.com/watch?v=CNTNypAG4S0

Halber, D. (1999). Different kinds of math use different parts of brain, research finds. MIT News.

Harnet, K. (2015). This is your brain on math. The Boston Globe.

National Center for Learning Disabilities. (2012, May 11). What is dyscalculia? [Video]. YouTube. https://www.youtube.com/watch?v=HVf_OHK2hHQ&list=PL60hj6d9o_BaLC3TZ_lar8gGTqbqk5lNR&index=2

Numerical Cognition Laboratory. (n.d.). Numeracy Screener. http://www.numeracyscreener.org/home.html

Titus, G. (2008). U.S. competitiveness in science and technology. RAND.

Understood. (2017, April 27). Understanding dyscalculia: Symptoms explained [Video]. YouTube. https://www.youtube.com/watch?v=GRJS-jeZ7Is

Understood. (2017, June 7). What is dyscalculia? [Video]. YouTube. https://www.youtube.com/watch?v=IezO567SKNM

Date of last update: 14-Dec-2022 CB

This resource is protected under a Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) license.