Klooster, Dale H., author
South-Western, 1990
Buku Teks
Hall, James A., author
South-Western College , 2001
Buku Teks
Wilkinson, Joseph W., author
John Wiley & Sons, 1991
Buku Teks
Boockholdt, James L., author
McGraw-Hill, 1999
Buku Teks
Clark, Frank
Goodyear Publishing Company , 1971
Buku Teks