Foto N. Afrati Evripidis Bampis Chandra Chekuri David R. Karger Claire Kenyon Sanjeev Khanna Ioannis Milis Maurice Queyranne Martin Skutella Clifford Stein Maxim Sviridenko Approximation Schemes for Minimizing Average Weighted Completion Time with Release Dates. 32-44 1999 conf/focs/1999 FOCS http://doi.ieeecomputersociety.org/10.1109/SFFCS.1999.814574 db/conf/focs/focs99.html#AfratiBCKKKMQSSS99