ENGEL, U. Wortklassen. Studia Germanica Posnaniensia, [S. l.], v. 16, p. 81–109, 2018. DOI: 10.14746/sgp.1989.16.05. Disponível em: https://pressto.amu.edu.pl/index.php/sgp/article/view/15996. Acesso em: 6 cze. 2023.