- "Encyclopedia of Play in Today's society" by Rodney P. Carlisle (Sage Publications) 2009 DOI: http://dx.doi.org.libproxy.wlu.ca/10.4135/9781412971935.n9
- "Dictionary of Toys and Games in American Culture" by Frank Hoffman et al, (Routledge) 2013
- "Encyclopedia of Video Games the culture, the technology, and art of gaming" by Mark Wolf, (California: Greenwood) c2012 [on order]
- "Plunkett's games, apps & social media industry almanac" by Jack W. Plunkett, (Texas: Plunkett Research) 2011-