Lai, Hollis, Mark J. Gierl, and Oksana Babenko. “Application of Conditional Means for Diagnostic Scoring”. International Journal of Learning, Teaching and Educational Research 12, no. 3 (July 30, 2015): 61–79. Accessed September 15, 2026. https://www.ijlter.myres.net/index.php/ijlter/article/view/1050.