Stability of steady-state motions of systems of symmetric rigid bodies with ball-and-socket joints. Annual of Sofia University St. Kliment Ohridski. Faculty of Mathematics and Informatics, [S. l.], v. 87, p. 337–349, 1995. Disponível em: https://annual.uni-sofia.bg/index.php/fmi/article/view/426. Acesso em: 15 dec. 2025.