Dearden, John, 1919-2004
Prentice-Hall, 1962
Buku Teks
Colm, Gerhard, author
Brookings Institution , 1969
Buku Teks
Mattessich, Richard, author
Richard D. Irwin, 1964
Buku Teks
Palsrok, John
Bairut s.n. 1968, [date of publication not identified]
Buku Teks
Paton, George Whitecross
Oxford University Press, 1964
Buku Teks