Jamil, S., R. H. Tariq, and M. Jamil. “School Type and Gender Wise Studies of Understanding of Three Dimensional Diagrams Among Children’s of 8 Years of Age”. Pakistan Journal of Social Sciences, vol. 36, no. 2, Dec. 2016, pp. 635-40, https://pjss.bzu.edu.pk/index.php/pjss/article/view/448.