LIGĘZA, Jan. The distributional solutions of some systems of linear differential equations. Annales Mathematicae Silesianae, [S. l.], v. 3, p. 82–90, 1990. Disponível em: https://trrest.vot.pl/ojsus/index.php/AMSIL/article/view/14306. Acesso em: 7 may. 2025.