Silitonga, R H Yanti, et al. “INCREASING MATHEMATICAL PROBLEM-SOLVING ABILITIES USING VIDEO TUTORIALS OF THE THREE-DIMENSIONAL COORDINATE SYSTEM IN SPATIAL ANALYTIC GEOMETRY”. JOHME: Journal of Holistic Mathematics Education, vol. 7, no. 2, Dec. 2023, pp. 212-26, doi:10.19166/johme.v7i2.7575.