1. Allen, T. (2022). 10 barriers to faith growth. Kalam Hidup. Google Scholar.
2. The concept of time management based on Ephesians 5: 15–17 and relevance to contemporary Christian leaders;Andrian T.;HTS Teologiese Studies/Theological Studies,2021
3. The proactive component of organizational behavior: A measure and correlates
4. Cascio, W. (1978). Applied psychology in personnel management. Reston Publishing Company, Inc. Google Scholar.
5. Covey, S. (2001). The 7 habits of highly effective teens. Literacy Development. Google Scholar.