AHRENS, Andreas; ZASCERINSKA, Jelena. Principles of Sampling in Educational Research in Higher Education. SOCIETY. INTEGRATION. EDUCATION. Proceedings of the International Scientific Conference, Rezekne, Latvia, v. 1, p. 25–35, 2015. DOI: 10.17770/sie2015vol1.310. Disponível em: https://archive-journals.rtu.lv/sie/article/view/1056.. Acesso em: 11 mar. 2026.