M. Breunig, H. Kriegel, P. Kröger, and J. Sander. SIGMOD '01: Proceedings of the 2001 ACM SIGMOD international conference on Management of data, page 79--90. New York, NY, USA, ACM, (2001)
P. Chan, M. Schlag, and J. Zien. DAC '93: Proceedings of the 30th international conference on Design automation, page 749--754. New York, NY, USA, ACM, (1993)