Modern Pocket Library, 1953
Buku Teks
Spencer, Herbert
Watts & CO., 1950
Buku Teks
MacIver, Robert M.
Oxford, 1926
Buku Teks
Cassirer, Ernst, editor
Yale University Press, 1961
Buku Teks
Seckler-Hudson, Catheryn
United State Information Service, 1959
Buku Teks