Paneva-Konovska Й.; Kiryakova В.; Davidov Й. Ninetieth anniversary of professor Peter Rusev. Mathematics and Education in Mathematics, [S. l.], v. 51, p. 32–40, 2022. Disponível em: https://smb.math.bas.bg/mem/index.php/memjournal/article/view/50. Acesso em: 5 oct. 2026.