Yao, Koffi. “The Variability of Ser and Estar (Spa.) Versus the Ambivalence of être (Fr.): Values and Didactic Models”. e-Scripta Romanica 3 (December 30, 2016): 75–95. Accessed February 7, 2026. https://czasopisma.uni.lodz.pl/escripta/article/view/4192.