Zhelyazkova Ц.; Boykina Д. Using a heuristic approach in maths education in 6th - 7th grade. Mathematics and Education in Mathematics, [S. l.], v. 50, p. 252–260, 2021. Disponível em: https://smb.math.bas.bg/mem/index.php/memjournal/article/view/31. Acesso em: 5 oct. 2026.