Helmi, Rustaman, N.Y., Tapilouw, F.S. and Hidayat, T. 2019. Students’ Concept Mastery: Reasoning Ability and Concept Mastery of Evolution. Indonesian Journal of Social Research (IJSR). 1, 1 (Aug. 2019), 23-29. DOI:https://doi.org/10.30997/ijsr.v1i1.7.