Keegan, John, author
Pimlico, 1994
Buku Teks
edited by Geoffrey Parker
Cambridge University Press, 1995
Buku Referensi
edited by Geoffrey Parker
Cambridge University Press, 1995
Buku Referensi
Preston, Richard Arthur, author
Praeger, 1962
Buku Teks
Ralby, Aaron, author
Parragon Books, 2013
Buku Referensi