8Adam Ferguson, An Essay on the History of Civil Society, edited with an introduction by Duncan Forbes, Edinburgh: Edinburgh University Press, 1966 [1767], p. 178.
9Georg Simmel, Conflict and the Web of Group Affiliations, trans, by Kurt H. Wolff and Reinhard Bendix, New York: Free Press, 1964, p. 15.
10Lewis A. Coser, The Functions of Social Conflicts, New York: Free Press, 1956, p. 105.
