Splinter, John P., author
Zondervan Publishing House, 1992
Buku Referensi
Brenner, Gary, author
Prentice-Hall, 1990
Buku Referensi
Jorgensen, Finn, author
The McGraw-Hill Companies, 1996
Buku Referensi
Szenasy, Susan S., author
Running Press, 1986
Buku Referensi
Bochinski, Julianne Blair, author
John Wiley & Sons, 1996
Buku Referensi