KENDEROV, P. Seventieth Anniversary of Professor Vesselin Stoyanov Drensky. Mathematics and Education in Mathematics, [S. l.], v. 50, p. 23–31, 2022. Disponível em: https://smb.math.bas.bg/mem/index.php/memjournal/article/view/3. Acesso em: 5 oct. 2026.