Hale, John R., author
Time-Life Books, 1974
Buku Teks
Arnold, David, author
Routledge, 1994
Buku Teks
Hewitt, James, author
Wayland, 1979
Buku Teks
Chaunu, Pierre
North-Holland Publishing Co., 1979
Buku Teks
Cushner, Nicholas P., author
Ateneo de Manila University Press, 1966
Buku Teks