Wahyuni, Vera. “Aiken Index Analysis to Determine The Contents Validity of Project Assessment Instrument in Learning Islamic Religion and Character in the Independent Curriculum”. Jurnal Sustainable 6, no. 2 (Desember 13, 2023): 565-569. Diakses Juli 5, 2025. https://www.lp2msasbabel.ac.id/jurnal/sus/article/view/4043.