Guerra, Y., Mendieta, . A. L., Acosta, . J., Vargas, V., & De Gracia, . E. (2013). Main factors that affect the low academic performance of the english subject from 9th grade students, in Daniel Octavio Crespo High School, Concepcion, Bugaba Chiriquí, 2013. David, Panamá: UDELAS.

Guerra, Yenisbeth, Ana Leticia Mendieta, Jorge Acosta, Victor Vargas, and Edward De Gracia. Main Factors That Affect the Low Academic Performance of the English Subject From 9th Grade Students, in Daniel Octavio Crespo High School, Concepcion, Bugaba Chiriquí, 2013. David, Panamá: UDELAS, 2013.

Guerra, Yenisbeth, et al. Main Factors That Affect the Low Academic Performance of the English Subject From 9th Grade Students, in Daniel Octavio Crespo High School, Concepcion, Bugaba Chiriquí, 2013. David, Panamá: UDELAS, 2013.