Gilbert, Neil, author
Prentice-Hall, 1986
Buku Teks
Australian council of social service, 0
Buku Teks
Schneider, Jo Anne, author
Columbia University Press, 2006
Buku Teks
Timms, Rita, author
Routledge, 1982
Buku Referensi
Gilbert, Neil, author
Allyn and Bacon, 1998
Buku Teks