Approximation, Randomization and Combinatorial Optimization. Algorithms and Techniques 11th International Workshop, APPROX 2008, and 12th International Workshop, RANDOM 2008, Boston, MA, USA, August 25-27, 2008. Proceedings - Goel, Ashish; Jansen, Klaus; Rolim, José D. P.; Rubinfeld, Ronitt (Springer Berlin Heidelberg, 2008)