1. Anton Trstenjak Institute of Gerontology and Intergenerational Relations. (2013). Anton Trstenjak Institute of Gerontology and Intergenerational Relations.
http://www.inst-antonatrstenjaka.si/old/eng/
. Accessed 16 Aug 2013.
2. Association of Slovenian Adult Education Centres. (2013). About the Association of Slovenian Adult Education Centres.
http://www.zlus.si/eng/index.aspx
. Accessed 19 Sept 2013.
3. Bogataj, N, (2012). Analiza študijskih krožkov. (Analysis of study circles. Report). Ljubljana: Andragoški center Slovenije.
4. Day Activity Centres. (2013). DCA Ljubljana-Dnevni centri aktivnosti za starejše (DAC Ljubljana-Day activity centres for older people).
http://www.dca-ljubljana.org/index.html
. Accessed 11 Aug 2013.
5. Elias, J. L., & Merriam, S. B. (2005). Philosophical foundations of adult education (3rd ed.). Malabar: Krieger.