RACLAVSKÝ, J.; KUCHYŇKA, P. Conceptual and derivation systems. Logic and Logical Philosophy, [S. l.], v. 20, n. 1-2, p. 159–174, 2011. DOI: 10.12775/LLP.2011.008. Disponível em: https://apcz.umk.pl/LLP/article/view/LLP.2011.008. Acesso em: 4 jul. 2024.