VanGuilder, Cliff
Mercury Learning and Information, 2014
Buku Teks
Syngress, 2013
eBooks
Ginsburg, Jane C., author
Michie, 1996
Buku Teks
Nelson, Grant S., author
West Publishing, 1992
Buku Teks
A. Roger Greenway, editor-in-chief
McGraw-Hill, 2000
Buku Referensi