Kadushin, Alfred, author
Columbia University Press, 2014
Buku Teks
Dubois, Brenda, 1949-, author
Allyn and Boston, 1992
Buku Teks
Gore, M.S., author
Asia Publishing House, 1965
Buku Teks
Cohen, Nathan Edward, author
National Ass. of Workker, 1964
Buku Teks
Gray, Ivan, author
Learning matters Ltd., 2010
Buku Teks