edited by James Midgley, David Piachaud
St. Martin's Press, 1984
Buku Teks
Bryman, Alan, author
Oxford University Press, 2016
Buku Teks
Moser, Claus A., author
Basic Books, 1972
Buku Teks
Moser, Claus A., author
Heinemann Educational Books, 1974
Buku Teks
Bank, Marcus, author
Sage Publications, 2001
Buku Teks