1. Munden S. 2012 London Chartered Quality Institute http://archive-org-2012.com/org/t/2012-12-25_1062943_26/Managing-continual-improvement-Chartered-Quality-Institute/
2. 2017 2nd ed Farmington Hills, MI Gale http://www.referenceforbusiness.com/encyclopedia/Per-Pro/Professional-and-Trade-Organizations.html
3. 2014 http://www.mci-group.com/en-GB/latest_articles/Navigating%20the%20Major%20Trends%20Affecting%20Associations