Capron, H.L.
The Benjamin / Cumming Publishing Company Inc., 1989
Buku Teks
Rude, Robert T., 1942-
Prentice-Hall, 1986
Buku Teks
Greenfield, Joseph D.
John Wiley & Sons, 1988
Buku Teks
Culey, Ray T.
South-Western Publishing, 1953
Buku Teks
Silvoso, Joseph A.
Ohio South-Western, 1965
Buku Teks