Peter F. Drucker, Joan Snyder Kuhl, Frances Hesselbein (2015). “Peter Drucker's Five Most Important Questions: Enduring Wisdom for Today's Leaders”, p.85, John Wiley & Sons
Speech on the Occasion of the Opening of the Governor General's Canadian Leadership Conference by Adrienne Clarkson in Winnipeg, archive.gg.ca. May 07, 2004.