Paton, George Whitecross
The Clarendon Press, 1953
Buku Teks
Broom, Leonard
Harper, 1981
Buku Teks
Broom, Leonard
Harper & Row, 1977
Buku Teks
Delong, Thomas, author
McGraw-Hill Irwin, 2003
Buku Teks
Mannheim, Hermann, author
Routledge & Kegan Paul, 1970
Buku Teks