1. Baral, S. M. (2014). Learning as leisure among older adults: Triggers, motivations and constraints of OLLI members (Unpublished thesis). Clemson University, Clemson.
2. Bernard Osher Foundation. (2005). Osher lifelong learning institutes. Retrieved from https://www.osherfoundation.org/index.php?olli
3. Motivational Factors and Predictors for Attending a Continuing Education Program for Older Adults
4. Ching, C. E. E. (2010). Later-life learning: A case study of YAH! Community college (Unpublished thesis). National University of Singapore, Singapore.