http://www.cnblogs.com/zhuyp1015/archive/2012/08/23/2653264.html
http://bbs.chinaunix.net/thread-4245729-1-1.html
http://www.pagefault.info/?p=403
http://www.aiuxian.com/relative/p-1655549.html
http://www.aiuxian.com/article/p-1655549.html
http://www.aiuxian.com/article/p-321011.html
原文：http://www.cnblogs.com/youngvoice/p/5901981.html