Pritchett, C. Herman
University of North California Press, 1943
Buku Teks
Quah, Jon S. T.
Talisman Pub, 2010
Buku Teks
Organisation for Economic Co-operation and Development (OECD)
Frederich-Naumann-Stiftung, 2002
Buku Teks
McGraw-Hill, 2013
Buku Teks
Parsons, Wayne
Kencana Prenada Media Group, 2011
Buku Teks