Nikhil Bansal Zachary Friggstad Rohit Khandekar Mohammad R. Salavatipour A logarithmic approximation for unsplittable flow on line graphs. 702-709 2009 SODA http://doi.acm.org/10.1145/1496770.1496847 conf/soda/2009 db/conf/soda/soda2009.html#BansalFKS09