Amery, Colin, Curran, Brian & Molodkovets, Yuri (2006): . London: Frances Lincoln, ISBN 0-7112-2492-7. Bater, James H. (1976): . Montreal: McGuill-Queen’s University Press, ISBN 0-7735-0266-1. Ruble, Blair A. (1990): . Berkeley: University of California Press. ISBN 0877723478.