Livingstone, D. “Re-Exploring the Icebergs of Adult Learning: Comparative Findings of the 1998 and 2004 Canadian Surveys of Formal and Informal Learning Practices”. Canadian Journal for the Study of Adult Education, vol. 20, no. 2, Dec. 2007, pp. 1-24, https://cjsae.library.dal.ca/index.php/cjsae/article/view/1104.