Maurice Cheung, David B. Shmoys. A Primal-Dual Approximation Algorithm for Min-Sum Single-Machine Scheduling Problems. In Leslie Ann Goldberg, Klaus Jansen, R. Ravi, José D. P. Rolim, editors, Approximation, Randomization, and Combinatorial Optimization. Algorithms and Techniques - 14th International Workshop, APPROX 2011, and 15th International Workshop, RANDOM 2011, Princeton, NJ, USA, August 17-19, 2011. Proceedings. Volume 6845 of Lecture Notes in Computer Science, pages 135-146, Springer, 2011. [doi]