HUBUNGAN SIBLING RIVALRY TERHADAP MOTIVASI BERPRESTASI PESERTA DIDIK SMP NEGERI 2 KOTO BARU. j. manaj. pendidik. [Internet]. 2025 Sep. 21 [cited 2026 May 28];10(3):1277-88. Available from: https://ejurnal.stkip-pessel.ac.id/index.php/jmp/article/view/759