MacIver, Robert M.
Democracy and the economic challenge
Alfred A. Knopf, 1952
 Buku Teks
Yu Keping
Democracy in China: Challenge and opportunity
Central Compilation Press, 2015
 eBooks
Janda, Kenneth
The challenge of democracy : government in America 1999-2000 update
Houghton Mifflin, 2000
 Buku Teks SO
The challenge of democracy American government in global politics
Kenneth Janda, Jeffrey M. Berry, Jerry Goldman, Deborah J. Schildkraut, Paul Manna
Cengage Learning, 2018
 Buku Teks SO
Data protection and privacy : jurisdictional comparisons
Monika Kuschewsky, general editor
Thomson Reuters, 2012
 Buku Teks