http://www.bbc.com/news/world-37352326http://www.nydailynews.com/sports/more-sports/wada-hacked-russian-group-williams-records-released-article-1.2790685http://www.focus.de/sport/tennis/dokumente-aufgetaucht-mit-ausnahmegenehmigung-gedopt-hackergruppe-belastet-williams-schwestern_id_5933963.htmlhttp://www.telegraph.co.uk/sport/2016/09/13/us-superstars-serena-and-venus-williams-and-simone-biles-given-d/http://www.nzherald.co.nz/sport/news/article.cfm?c_id=4&objectid=11709288