Barney, George C.
Prentice-Hall, 1988
Buku Teks
Bentley, John P.
John Wiley & Sons, 1988
Buku Teks
Steckhahn, A.D.
Reston Publishing, 1982
Buku Teks
Bibbero, Robert J.
John Wiley & Sons, 1977
Buku Teks SO
Johnson, Curtis D., 1939-
Prentice Hall Career and Technology, 1993
Buku Teks