some useful links

http://bbs.wenxuecity.com/finance/3344607.html

一个按月定期投资计算器 ZT

http://bbs.wenxuecity.com/finance/3367196.html

双子塔

http://seekingalpha.com/instablog/14324642-growfast/2634551-dgaz-risk-analysis?source=kizur_seekingalpha

DGAZ Risk Analysis