Rapley, John
Lynne Rienner, 2007
Buku Teks
Melkote, Srinivas
Newbury Park, Calif. : Sage Publications,, 1991
Buku Teks
Dixon, Chris J.
Routledge, 2015
Buku Teks
Todaro, Michael P.
Longman, 1992
Buku Teks
Handelman, Howard
Pearson/Prentice Hall, 2006
Buku Teks