http://www.ruanyifeng.com/blog/2010/04/using_this_keyword_in_javascript.html

http://www.cnblogs.com/philzhou/p/3282216.html

http://www.cnblogs.com/justany/archive/2012/11/01/the_keyword_this_in_javascript.html

http://www.ibm.com/developerworks/cn/web/1207_wangqf_jsthis/

http://www.cnblogs.com/uedt/articles/1748422.html

http://www.cnblogs.com/felix2007/archive/2007/03/21/682670.html

http://yehudakatz.com/2011/08/11/understanding-javascript-function-invocation-and-this/

http://unschooled.org/2012/03/understanding-javascript-this/

http://jibbering.com/faq/notes/closures/

JS This关键字