Cohen, Nathan Edward, author
National Ass. of Workker, 1964
Buku Teks
Dubois, Brenda, 1949-, author
Allyn and Boston, 1992
Buku Teks
Australian council of social service, 0
Buku Teks
Timms, Rita, author
Routledge, 1982
Buku Referensi
Young, Pat, author
Macmillan, 1995
Buku Teks