↑ Oliver H. Woshinsky. Explaining Politics: Culture, Institutions, and Political Behavior. Oxon, England; New York, New York, USA: Routledge, 2008. Pp. 141, 161.
↑ Boswell, Jonathan (2013). Community and the Economy: The Theory of Public Co-operation. Routledge. m/s. 160. ISBN9781136159015.
