Rees, Leslie, 1905-2000, author
Angus and Roberson, 1973
Buku Teks
Nicoll, Allardyce, author
George G. Harrap, 1949
Buku Teks
Western Press Agency, 1962
Buku Teks
Easton, Stewart C., author
Praeger, 1964
Buku Teks
Zeitlin, Irving M., author
Polity Press, 2007
Buku Teks