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"Becoming a Great School: Harnessing the Powers of Quality Management and Collaborative Leadership". Book by Dr. Kenneth B. Cooper, Nels Gustafson and Joseph G. Salah (p. 9), December 24, 2013.
Theodore Roosevelt (2015). “Theodore Roosevelt on Bravery: Lessons from the Most Courageous Leader of the Twentieth Century”, p.13, Skyhorse Publishing, Inc.
Theodore Roosevelt (2015). “Theodore Roosevelt on Bravery: Lessons from the Most Courageous Leader of the Twentieth Century”, p.31, Skyhorse Publishing, Inc.
Theodore Roosevelt (2015). “Theodore Roosevelt on Bravery: Lessons from the Most Courageous Leader of the Twentieth Century”, p.28, Skyhorse Publishing, Inc.