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
Berlin : Mouton Publishers
Majalah, Jurnal, Buletin