Sagala, Prima V, et al. “HUBUNGAN ANTARA KECERDASAN SPIRITUAL (SI) DENGAN HASIL BELAJAR KOGNITIF SISWA KELAS VIII SMPK KALAM KUDUS YOGYAKARTA PADA PEMBELAJARAN MATEMATIKA [THE RELATIONSHIP BETWEEN SPIRITUAL INTELLIGENCE (SI) AND COGNITIVE LEARNING OUTCOMES OF GRADE 8 STUDENTS SMPK KALAM KUDUS YOGYAKARTA IN LEARNING MATHEMATICS]”. JOHME: Journal of Holistic Mathematics Education, vol. 2, no. 1, Dec. 2018, pp. 22-33, doi:10.19166/johme.v2i1.1021.