Hoefer, Martin Algorithms and Complexity, MPI for Informatics, Max Planck Society;
Link (beliebiger Volltext)
Hoefer, M., Kesselheim, T., & Vöcking, B. (2014). Approximation Algorithms for Secondary Spectrum Auctions. ACM Transactions on Internet Technology, 14(2-3): 16, pp. 1-24. doi:10.1145/2663496.