Manik, Alusti Cundo, Hari Sutrisno, and Ifan Rivaldo. “Testing the Validity and Reliability of Conceptual Chemistry Learning Instruments During the COVID-19 Pandemic Using Rasch Modeling”. Jurnal Penelitian Pendidikan IPA 8, no. 3 (July 31, 2022): 1561–1568. Accessed April 18, 2024. https://jppipa.unram.ac.id/index.php/jppipa/article/view/1486.