Cribb, R.B., Kahin, A. (2004): , Scarecrow Press Dick, Howard, et al. (2002): , University of Hawaii Press Friend, T. (2003): . Harvard University Press. ISBN 0-674-01137-6. Ricklefs, M.C. (1991): , 2. utg. MacMillan. ISBN 0-333-57690-X. Kapitlene 10–15. Taylor, Jean Gelman (2003): . New Haven and London: Yale University Press. ISBN 0-300-10518-5. Vickers, Adrian (2005): . Cambridge University Press. ISBN 0-521-54262-6.