Henley, Ernest J.
John Wiley & Sons, 1981
Buku Teks
Masters, Gilbert M.
Prentice-Hall, 2008
Buku Teks
Greenkorn, R.A.
McGraw-Hill, 1972
Buku Teks
McPartland, Joseph F.
McGraw-Hill, 1996
Buku Referensi
Masters, Gilbert M.
Prence Hall International , 1991
Buku Teks