Michael, Donald N.
Jossey-Bass, 1985
Buku Teks
Cooper, Robert L., author
Cambridge University Press, 1989
Buku Teks
Morris, Robert, author
Columbia University Press , 1966
Buku Teks
Waterston, Albert, author
John Hopkins University Press, 1969
Buku Teks
Walter, Gordon A.
John Wiley , 1981
Buku Teks