Haiman, A., Lockwood, M. y Walicek, D. E. (2017) «The Teaching of English at U.P.R.R.P., F.E.G.: A model for reflexive, critical and creative thinking about language», Revista Umbral, (4), pp. 39–65. Disponible en: https://revistas.upr.edu/index.php/umbral/article/view/8446 (Accedido: 10 agosto 2022).