Escalona-Pardo, E., Pantoja-Tamayo, L. e Frías-Reyes, Y. 2018. A system of language games for improving the speaking skill in tenth graders at Micaela Riera Oquendo senior high school in Manzanillo (Original). Roca. Revista científico - educacional de la provincia Granma. 14, 2 (jun. 2018), 41-49.