Amadeo, Santos P.
Columbia University Press, 1943
Buku Teks
Wheare, K. C., author
Pustaka Eureka, 2005
Buku Teks
Amery, L.S., author
Oxford University Press, 1953
Buku Teks
Corwin, Edward S., author
William Sloane, 1949
Buku Teks
Jennings, Ivor, Sir, 1903-1965, author
Hodder and Stoughton, 1979
Buku Teks