Gupan, Nestor. “School Textbook As a Source of Study of Differentiation of Content of Social Science Subjects (40 – 50s of ХХ Century)”. Pedagogical Discourse0, no. 15 (October 3, 2013): 185-190. Accessed July 27, 2024. http://ojs.kgpa.km.ua/index.php/peddiscourse/article/view/695.