Purnamasari, Untung Desy, and Badrun Kartowagiran. “Application Rasch Model Using R Program in Analyze the Characteristics of Chemical Items”. Jurnal Inovasi Pendidikan IPA 5, no. 2 (October 29, 2019): 147–156. Accessed May 15, 2025. https://jurnal.uny.ac.id/index.php/jipi/article/view/24235.