http://www.tradersmagazine.com/news/nyse-nasdaq-bats-exchanges-fight-for-etf-share-111140-1.html

http://www.foxnews.com/tech/2013/04/28/facebook-ceo-mark-zuckerberg-realized-23-billion/

http://www.chicagobusiness.com/article/20130427/ISSUE07/304279993/cme-nothing-less-than-transparency-will-do

http://www.reuters.com/article/2013/04/26/us-cboe-delay-fixed-idUSBRE93P1BZ20130426

http://www.chicagobusiness.com/article/20130429/NEWS01/130429795/glitch-may-press-cboe-to-let-popular-products-trade-elsewhere

http://www.upi.com/Science_News/Technology/2013/04/27/CBOE-getting-to-bottom-of-glitch/UPI-77201367075042/

http://www.bloomberg.com/news/2013-04-26/the-market-s-twitter-jitters.html

http://online.barrons.com/article/SB50001424052748703889404578438860106833412.html?mod=BOL_hpp_mag

http://www.tradersmagazine.com/news/options-dealers-petition-sec-block-order-exposure-rule-111138-1.html

http://www.reuters.com/article/2013/04/26/cboe-options-volume-idUSL2N0DD2FA20130426

http://www.reuters.com/article/2013/04/26/us-cboe-glitch-idUSBRE93P0W420130426?feedType=RSS&feedName=domesticNews

http://online.barrons.com/article/SB50001424052748703889404578446831753428950.html?mod=BOL_da_spd