1. Old Hong Kong. Volume II: 1901-1945;Wiltshire,1997
2. Which Chinese? Dialect Choice in Philadelphia’s Chinatown (PDF);Yum,2007
3. http://www.censtatd.gov.hk/hkstat/sub/so20.jsp.
4. http://www.gov.hk/en/about/abouthk/facts.htm.
5. http://www.indexmundi.com/hong_kong/demographics_profile.html.