Muhammad Abdullah. “STANDARDS AND METHODS OF VALIDITY AND RELIABILITY TESTING OF QUESTIONNAIRES USED IN SOCIAL AND HEALTH SCIENCE RESEARCHES”. PAKISTAN JOURNAL OF LINGUISTICS 2, no. 4 (December 5, 2020): 8-19. Accessed May 18, 2021. https://pjl.com.pk/index.php/PJL/article/view/609.