This scholarly article provides an in-depth literature review of pivotal research studies focused on values-based leadership. The author traces the development of values-based leadership research chronologically, centered around authentic, ethical, and transformational leadership.

Copeland, M. K. (2014). The emerging significance of values-based leadership. International Journal of Leadership Studies, 8(2), 105-135.
https://www.regent.edu/acad/global/publications/ijls/new/vol8iss2/6-Copeland.pdf