Lisyová, Ol’ga. “On the Definition of Periphrastic Verbal Constructions in Spanish Language (doubts and Contradictions)”. Studia Romanica Posnaniensia 31 (December 1, 2004): 329–342. Accessed September 27, 2024. https://pressto.amu.edu.pl/index.php/srp/article/view/10249.