edited by Trevor Harley
Sage, 2011
Buku Teks
Garman, Michael
Cambridge University Press, 1990
eBooks
edited by Sheldon Rosenberg
Macmillan, 1965
Buku Teks
Warren, Paul, 1958-
Cambridge University Press, 2013
eBooks
Field, John
Routledge, 2006
Buku Teks