Mitchell, Robert L.
John Wiley & Sons, 1980
Buku Teks
Riggs, James L.
McGraw-Hill, 1982
Buku Teks
Spencer, Milton H.
Worth, 1971
Buku Teks
Thuesen, H.G.
Prentice-Hall, 1971
Buku Teks
McEachern, William A.
South-Western College Publishing, 1988
Buku Teks