Muller, Herbert J.
George Braziller, Inc., 1956
Buku Teks
Kymlicka, Will, author
Clarendon Press, 1990
Buku Teks
Gellner, Ernest, author
Routledge & Kegan Paul, 1974
Buku Teks
Benton, Ted, author
Design , 2001
Buku Teks
Phillips, D.C., author
Stanford University Press, 1976
Buku Teks