Cherry, Barbara, author
Elsevier , 2011
Buku Teks
Eyestone, Robert
John Wiley & Sons, 1978
Buku Teks
Brink, Pamela J., author
Jones and Bartlett, 1988
Buku Teks
Griffith, Richard, author
Learning matters Ltd., 2008
Buku Teks
Guido, Ginny Wacker, author
Prentice-Hall, 2006
Buku Teks