PĘKAŁA, Jan. G. On the axioms of quadratic form schemes. Annales Mathematicae Silesianae, [S. l.], v. 3, p. 24–31, 1990. Disponível em: https://trrest.vot.pl/ojsus/index.php/AMSIL/article/view/14298. Acesso em: 7 may. 2025.