PERRIG, Gabriela; PETER, Klaus; SCHÜMANN, Michael. Grammatik im DaF-Unterricht. Linguistik Online, Bern, v. 49, n. 5, 2011. DOI: 10.13092/lo.49.323. Disponível em: https://bop.unibe.ch/linguistik-online/article/view/323. Acesso em: 14 may. 2025.