Ismat, Shaista, and Junaid Saghir. “Measuring Intelligence by Raven Standard Progressive Matrices Test: A PCA Approach”. JISR management and social sciences & economics 10, no. 2 (December 31, 2012): 1–8. Accessed May 5, 2024. https://jisrmsse.szabist.edu.pk/index.php/szabist/article/view/206.