1. American Counseling Association 2016 20/20: Principles for unifying and strengthening the profession http://www.counseling.org/knowledge-center/20-20-a-vision-for-the-future-of-counseling/statement-of-principles
2. Professional practice, learning, and continuing education: An integrated perspective;Cervero;International Journal of Lifelong Education,1992
3. Understanding informality and formality in learning;Colley;Adults Learning,2003