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
Lahsasna, Ahcene
CERT, 2010
Buku Teks SO
Zamir Iqbal and Abbas Mirakhor, Editors
The World Bank, 2013
Buku Teks SO