Headington, Mark R.
Jones and Bartlett Publisher, 1997
Buku Teks
Grossberg, Alan B.
McGraw-Hill, 1971
Buku Teks
Cooper, James W.
John Wiley & Sons, 1981
Buku Teks
Rice, John K.
Holt, Rinehart and Winston , 1973
Buku Teks
Gehani, Narain, 1947-
Prentice-Hall, 1989
Buku Teks