Project scheduling with irregular costs: complexity, approximability, and algorithms.

Alexander Grigoriev Gerhard J. Woeginger Project scheduling with irregular costs: complexity, approximability, and algorithms. 83-97 2004 41 Acta Inf. 2-3 http://dx.doi.org/10.1007/s00236-004-0150-2 db/journals/acta/acta41.html#GrigorievW04