Holt, Renehart and Winston , 1971
Buku Teks
Havrilesky, Thomas M.
AHM Publishing , 1978
Buku Teks
Blanchard, Olivier, author
Pearson, 2009
Buku Teks
Blanchard, Oliver, author
Prentice-Hall, 1997
Buku Teks
Mankiw, N. Gregory, author
Worth, 1994
Buku Teks