1. The rise of crowdsourcing;Howe;Wired Mag.,2006
2. Crowdsourcing: How the Power of the Crowd Is Driving the Future of Business;Howe,2008
3. What Is Web 2.0? Design Patterns and Business Models for the Next Generation of Software;O’Reilly,2005
4. Citizens as sensors: The world of volunteered geography;Goodchild;GeoJournal,2007