Andriani, Lies. “Analisis Kesalahan Mahasiswa Dalam Meyelesaikan Soal Himpunan Di Program Studi Pendidikan Matematika UIN SUSKA RIAU”. Jurnal Cendekia : Jurnal Pendidikan Matematika 3, no. 2 (December 11, 2019): 550-562. Accessed July 10, 2020. https://j-cup.org/index.php/cendekia/article/view/146.