Sudirman, A., Lie, D., Sherly, S., & Dharma, E. (2020). The Impact of Work Discipline and Work Ethic on the Teacher Performance of Sultan Agung Pematangsiantar Private Middle School Teachers T.A. 2018/2019. International Journal of Business Studies, 3(3), 125–135. https://doi.org/10.32924/ijbs.v3i3.83