edited by Stephan Haggard, Chung H. Lee and Sylvia Maxfield
Cornell University Press, 1993
Buku Teks SO
Warde, Ibrahim
Edinburgh University Press, 2000
Buku Teks SO
Khan, Muhammad Akram
Routledge, 2003
Buku Referensi
Visser, Hans G.
Edward Elgar, 2009
Buku Teks SO
Muhammad Ayub
John Wiley & Sons Inc., 2010
Buku Teks SO