Khasna, Fenny Tanalinal, and Nuriyah Nuriyah. “Validity Analysis of the OIPE Model Teaching Materials With Experimental Methods to Train Critical Thinking Skills of Elementary School Students”. Jurnal Penelitian Pendidikan IPA 9, no. 5 (May 31, 2023): 3883–3889. Accessed November 22, 2024. https://jppipa.unram.ac.id/index.php/jppipa/article/view/3525.