Arèvalo Zarparte, J. L., Garcìa Mira, L. A., Guevara Romàn, E. R., Mazariego Santamarìa, J. F., & Rivas Alvarenga, C. A. (2015). Improving second year high school tourism students' english speaking skill at Centro Escolar INSA in the periods II and III during the school year 2015. Santa Ana, El Salvador: Universidad de El Salvador.

Arèvalo Zarparte, Jorge Luis, Luis Alonso Garcìa Mira, Evelin Roxana Guevara Romàn, Josè Francisco Mazariego Santamarìa, and Carlos Amìlcar Rivas Alvarenga. Improving Second Year High School Tourism Students' English Speaking Skill At Centro Escolar INSA in the Periods II and III During the School Year 2015. Santa Ana, El Salvador: Universidad de El Salvador, 2015.

Arèvalo Zarparte, Jorge Luis, et al. Improving Second Year High School Tourism Students' English Speaking Skill At Centro Escolar INSA in the Periods II and III During the School Year 2015. Santa Ana, El Salvador: Universidad de El Salvador, 2015.