Ariel Gabizon Ran Raz Ronen Shaltiel Deterministic Extractors for Bit-Fixing Sources by Obtaining an Independent Seed. 1072-1094 2006 36 SIAM J. Comput. 4 http://dx.doi.org/10.1137/S0097539705447049 db/journals/siamcomp/siamcomp36.html#GabizonRS06