WELAN, Clive Johday. PENERAPAN MODEL PROBLEM SOLVING LEARNING UNTUK MENINGKATKAN HASIL BELAJAR KOGNITIF SISWA KELAS XI PADA MATERI KONFLIK SOSIAL DI SALAH SATU SMA DI SURABAYA [THE IMPLEMENTATION OF PROBLEM-SOLVING LEARNING MODELS TO IMPROVE STUDENTS COGNITIVE ACHIEVEMENT ON CONFLICT OF GRADE XI SENIOR HIGH SCHOOL IN ONE OF THE HIGH SCHOOL IN SURABAYA]. Kumpulan Artikel Ilmiah Rumpun Ekonomi dan Ilmu Sosial, [S. l.], v. 3, n. 1, p. 88–107, 2023. DOI: 10.19166/kairos.v3i1.6145. Disponível em: https://ojs.uph.edu/index.php/KAIROS/article/view/6145. Acesso em: 28 feb. 2025.