Almeida, C.; Casas García, L.; Luengo González, R. Study of the Cognitive Structure of Portuguese Students in Years 9 (14-15 Year-Olds) and 12 (17-18 Year-Olds) Concerning the Notion of Probability: A Contribution of Theories of Nuclear Concepts and Threshold Concepts. RELIME 2017, 20 (1), 9-38. https://doi.org/10.12802/relime.17.2011.