The World's religions
edited by Stewart Sutherland, Leslie Houlden, Peter Clarke, Friedhelm Hardy
Routledge, 1988
 Buku Referensi
Fryer, D.W.
World economic development
McGraw-Hill, 1965
 Buku Teks
World economic outlook
by International Monetary Fund
International Monetary Fund, 1999
 Buku Teks
Third world economic handbook
Euromonitor, 1989
 Buku Teks
Todaro, Michael P.
Economic development in the world
Longman, 1989
 Buku Teks