1. 1. Houle CO: The Inquiring Mind. Madison: University of Wisconsin Press 1961.
2. 2. Bevis ME: Role Conception and the Continuing Learning Activities of Neophyte Collegiate Nurses. Unpublished Ph.D. dissertation University of Chicago 1971.
3. 3. Litchfield A: The Nature and Pattern of Participation in Adult Education Activities. Unpublished Ph.D. dissertation University of Chicago 1965.
4. 4. Netheiton JD: The Relationship Between Educational Participation and Innovativeness of County Extension Agents. Unpublished Ph.D. dissertation University of Chicago 1967.
5. 5. Litchfield op cit. 38-39.