Gould, Nick
Routledge, 2016
Buku Teks
Healy, Karen
Palgrave Macmillan, 2005
Buku Teks
Golightley, Malcom
Learning matters Ltd., 2008
Buku Teks
Pritchard, Colin
Routledge, 2006
Buku Teks
edited by Lynn Videka-Sherman and William J. Reid
NASW Press, 1990
Buku Teks