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://journals.us.edu.pl/index.php/AMSIL/article/view/14345. Acesso em: 5 dec. 2025.