Laski, Harold J., author
George Allen and Unwin, 1949
Buku Teks
Cote, Piere-Andre
Les Editions Yvon Blais,Inc., 1991
Buku Teks
Selznick, Philip, author
Harper and Row , 1957
Buku Teks
William, Robin M.
Alfred, 1966
Buku Teks
Firth, Raymond, author
Routledge, 1996
Buku Teks