Artavia Moya, P., Gonzalez Carvajal, D., Rojas Arias, Y., & Valverde Rodriguez, G. (2002). An analysis of the socio-cultural content of the locally-produced series of fextbooks Have Fun, and a proposal for model complementary material on foreign culture awareness. Heredia, Costa Rica: P. Artavia M..

Artavia Moya, Paola,, Douglas Gonzalez Carvajal, Yorleny Rojas Arias, and Giovanni Valverde Rodriguez. An Analysis of the Socio-cultural Content of the Locally-produced Series of Fextbooks Have Fun, and a Proposal for Model Complementary Material On Foreign Culture Awareness. Heredia, Costa Rica: P. Artavia M., 2002.

Artavia Moya, Paola,, Douglas Gonzalez Carvajal, Yorleny Rojas Arias, and Giovanni Valverde Rodriguez. An Analysis of the Socio-cultural Content of the Locally-produced Series of Fextbooks Have Fun, and a Proposal for Model Complementary Material On Foreign Culture Awareness. Heredia, Costa Rica: P. Artavia M., 2002.