Treece, Marla, author
Allyn and Bacon, 1994
Buku Teks
Munter, Mary, author
Prentice-Hall, 1982
Buku Referensi
O`Hair, Dan, author
Kencana, 2009
Buku Teks
O`Hair, Dan, author
Allyn and Bacon, 2011
Buku Teks
Holt, Rinehart and Winston of Canada, Limited, 1988
Buku Teks