Bell, Phillip, author
Sage, 2001
Buku Teks
Matthews, Janice R., author
Cambridge University Press, 2016
Buku Teks
Alfaro, Rosalinda, author
J.B. Lippincott, 1990
Buku Teks
Baker, Sunny, author
Prentice-Hall, 1992
Buku Referensi
Johnson, Joyce Young, author
Lippincott , 1998
Buku Teks