Stefan S. Dantchev Barnaby Martin Mark Rhodes Tight rank lower bounds for the Sherali-Adams proof system. 2054-2063 2009 410 Theor. Comput. Sci. 21-23 http://dx.doi.org/10.1016/j.tcs.2009.01.002 db/journals/tcs/tcs410.html#DantchevMR09