Casey, Catherine
Routledge, 1995
Buku Teks
edited by Robert H. Beck
National Association of Social Workers, 1965
Buku Teks
Rivers, William L., author
Prenadamedia Group, 2015
Buku Teks
Artikel Jurnal
Hansen, Bertrand L., author
Prentice-Hall, 1960
Buku Teks