Esther M. Arkin Refael Hassin Shlomi Rubinstein Maxim Sviridenko Approximations for Maximum Transportation with Permutable Supply Vector and Other Capacitated Star Packing Problems. 175-187 2004 39 Algorithmica 2 http://dx.doi.org/10.1007/s00453-004-1087-0 db/journals/algorithmica/algorithmica39.html#ArkinHRS04