Vagts, Alfred, author
Greenwood Press, 1959
Buku Teks
Keegan, John, author
Pimlico, 1994
Buku Teks
Bannon, John Francis, author
McGraw-Hill, 1952
Buku Teks
Elton, Geoffrey Rudolph, author
Sydney University Press, 1967
Buku Teks
McCullagh, C. Behan, author
Routledge, 1998
Buku Teks