The Power of Positive Leadership: How and Why Positive Leaders Transform Teams and Organizations and Change the World by Jon Gordon

The Dichotomy of Leadership: Balancing the Challenges of Extreme Ownership to Lead and Win by Jocko Willink & Leif Babin

21 Irrefutable Laws of Leadership by John C. Maxwell

Tribes by Seth Godin

The 21 indispensable qualities of a leader by John C. Maxwell

The Servant: A Simple Story About the True Essence of Leadership by James C. Hunter

The Leader Who Had No Title by Robin Sharma

Primal Leadership: Learning to Lead with Emotional Intelligence by Daniel Goleman, Richard Boyatzis, Annie McKee

Leadership 2.0 by Travis Bradberry & Jean Greaves

Leadership & Self Deception: Getting Out of the Box by Arbinger Institute.