Bellido, W. A., and F. M. Rico. “Instructional Material Development for Vocabulary Enhancement of Grade 9 Students of Botolan National High School”. International Journal of Multidisciplinary: Applied Business and Education Research, Vol. 2, no. 12, Dec. 2021, pp. 1416-23, doi:10.11594/10.11594/ijmaber.02.12.15.