Groff, James R., author
Osborne/Mcgarw-Hill, 1999
Buku Referensi
Andersen, Virginia, author
McGraw-Hill, 2003
Buku Teks
Jones, Edward
McGraw-Hill, 1988
Buku Referensi
Hamilton, Graham, author
Addison-Wesley, 1997
Buku Teks
Fisher, Maydene, author
addison-Wesley, 2003
Buku Teks