Stephen R. Covey, A. Roger Merrill, Rebecca R. Merrill (1997). “First Things First Every Day: Daily Reflections- Because Where You're Headed Is More Important Than How Fast You Get There”, Simon and Schuster
Daniel Goleman, Richard Boyatzis, Annie McKee (2013). “Primal Leadership: Unleashing the Power of Emotional Intelligence”, p.99, Harvard Business Press