https://medium.com/@andersonorui_/bem-sass-and-bootstrap-9f89dc07d20f
http://www.smashingmagazine.com/2014/07/bem-methodology-for-small-projects/
http://www.smashingmagazine.com/2013/02/the-history-of-the-bem-methodology/
原文：http://www.cnblogs.com/kidsitcn/p/4856617.html