Barlow, David H., author
Thomson , 2005
Buku Teks
Semrud-Clikeman, Margaret, author
Allyn and Bacon, 1995
Buku Teks
edited by Fred E. Stickle
McGraw-Hill , 2012
Buku Teks
Phares, Vicky, author
John Wiley & Sons, 2003
Buku Teks
Sprintahall, Norman, author
McGraw-Hill , 1995
Buku Teks