Michael, author
Chronicle Books, 2000
Buku Referensi
Linton, Harold, author
McGraw-Hill, 1999
Buku Teks
Lancaster, Michael
Academy Editions, 1996
Buku Teks
Gill, Martha, author
Rockport Publishers, 2000
Buku Teks
Alexander, Kathie
Rockport Publishers, Inc., 2010
Buku Referensi