Daniel Bienstock Garud Iyengar Approximating Fractional Packings and Coverings in O(1/epsilon) Iterations. 825-854 2006 35 SIAM J. Comput. 4 http://epubs.siam.org/SICOMP/volume-35/art_44729.html db/journals/siamcomp/siamcomp35.html#BienstockI06