Itule, Bruce D., author
McGraw-Hill, 1994
Buku Teks
Dick, Jill, author
A and C Black, 1994
Buku Teks
Thornburg, Ryan, author
CQ Press, 2011
Buku Teks
Yates, Edward D., author
Contemporary Publishing Company, 1981
Buku Teks
Berner, R. Thomas, author
Allyn and Bacon, 1992
Buku Teks