Ewa Łętowska, Wzorce umowne. Ogólne warunki. Wzory. Regulaminy. [Les modèles contractuels. Conditions générales. Modèles. Règlements], Wrocław 1975, Ossolineum. Contemporary Central & East European Law, [S. l.], n. 1 (33), p. 47–49, 1977. Disponível em: https://czasopisma.inp.pan.pl/index.php/cceel/article/view/1454. Acesso em: 6 oct. 2025.