1. A. Trost, Human Resources Strategies. Cham: Springer International Publishing, 2020.
2. D. Gomez, Leadership Growth Through Crisis. Cham: Springer International Publishing, 2020.
3. K. J. K. H.-Y. Kim, Information Science and Applications, vol. 621. Singapore: Springer Singapore, 2020.
4. A. Rachman, “The Influence of Competence and Discipline of the Crew on the Performance of PT. Djakarta Lloyd,” Int. J. Innov. Creat. Chang., vol. 8, no. 12, pp. 253–269, 2019.
5. Influence of school leadership, discipline, and work motivation toward high school teacher performance