1. Analysys (易观国际). (2010). Chinese Group-buying transaction will reach 0.98 billion. (2010年中国团购网站市场交易规模将达到9.8亿.) Retrieved February 8, 2010, from http://www.analysys.com.cn/cache/1194/87542.html . Translated from Chinese language.
2. Anand, K. S., & Aron, R. (2003). Group buying on the web: A comparison of price-discovery mechanisms. Management Science, 49, 1546–1562.
3. Arrington, M. (2009). Groupon Gets A Hefty $30 Million From Accel For Local Offers Service. Retrieved February 8, 2011, from http://techcrunch.com/2009/12/02/groupon-gets-a-hefty-30-million-from-accel-for-local-offers-service/ .
4. Arrington, M. (2010). Copy/Paste Innovation: Groupon Gets Cloned in Russia and China. Retrieved February 8, 2011, from http://techcrunch.com/2010/04/04/cut-paste-innovation-groupon-gets-cloned-in-russia/ .
5. Banerjee, A. V. (1992). A simple model of herd behavior. Quarterly Journal of Economics, 107(3), 797–817.