Morton, Gene A.
Fishergate, 1986
Buku Teks
Black, Kenneth
Prentice-Hall, 2000
Buku Teks
Ingrisano, John R.
Chicago, Dearborn Financial Publishing, 1990
Buku Referensi
Black, Kenneth
Prentice-Hall, 1994
Buku Teks
Huebner, S. S.
Appleton-Century Crafts, 1958
Buku Teks