1. Beck L, Cable TT (2002) Interpretation for the 21st century: fifteen guiding principles for interpreting nature and culture, 2nd edn. Sagamore Publishing, Champaign, IL
2. Boyte HC (2005) Everyday politics: reconnecting citizens and public life. University of Pennsylvania Press, Philadelphia
3. Boyte HC, Shelby D (2008) The citizen solution: how you can make a difference. Historical Society Press, Minnesota
4. Corbett JA (2006) Communicating nature: how we create and understand environmental messages. Island Press, Washington
5. Cranton P (2006) Understanding and promoting transformative learning: a guide for educators of adults, 2nd edn. Jossey-Bass, San Francisco