KIERAT, Władysław. On a certain extensions of linear spaces with an algebraic derivation. Annales Mathematicae Silesianae, [S. l.], v. 1, p. 145–154, 1985. Disponível em: https://trrest.vot.pl/ojsus/index.php/AMSIL/article/view/14345. Acesso em: 7 may. 2025.