Jensen, G.
, Liveright, A., & Hallenbeck, W. (1964). Adult education: Outlines of an emerging field of university study. Washington, DC: Adult Education Association of the USA.
2.
Peters, J. M.
, Jarvis, P., & Associates. (Eds.). (1991). Adult education: Evolution and achievement in a developing field of study. San Francisco: Jossey-Bass.