On the investigations of Kiril Popoff in the field of ballistics (in Bulgarian). Annual of Sofia University St. Kliment Ohridski. Faculty of Mathematics and Informatics, [S. l.], v. 98, p. 11–23, 2008. Disponível em: https://annual.uni-sofia.bg/index.php/fmi/article/view/125. Acesso em: 11 jan. 2026.