Sorto, M. Alejandra, et al. “TEACHER KNOWLEDGE AND TEACHING IN PANAMA AND COSTA RICA: A COMPARATIVE STUDY IN PRIMARY AND SECONDARY EDUCATION ”. Revista Latinoamericana De Investigación En Matemática Educativa, vol. 12, no. 2, Apr. 2009, pp. 251-90, https://www.relime.org/index.php/relime/article/view/337.