Alpya, Lily, Elvina Elvina, and Mulya Rafika. 2022. “Human Resources Performance Improvement Through Motivation, Disipline, Work Environment, and Commitment in PT. Supra Matra Abadi PMKS Aek Nabara”. Quantitative Economics and Management Studies 3 (4):515-24. https://doi.org/10.35877/454RI.qems982.