@article{STT81
, author =      "K. Sugiyama and S. Tagawa and M. Toda"
, title =       "Methods for Visual Understanding of Hierarchical Systems"
, journal =     "IEEE Trans. Syst. Man Cybern."
, volume =      "SMC-11"
, number =      2
, year =        1981
, pages =       "109--125"
}
@article{Car80
, author =      "M. J. Carpano"
, title =       "Automatic Display of Hierarchized Graphs for Computer Aided Decision Analysi
s"
, journal =     "IEEE Trans. Syst. Man Cybern."
, volume =      "SMC-10"
, number =      11
, year =        1980
, pages =       "705--715"
}
@article{GJ83,
author={M.R. Garey and D.S. Johnson},
title={Crossing number is {NP}-complete},
journal={SIAM J. Algebraic Discrete Methods},
volume={4},
year={1983},
pages={312--316}
}
@article{EW94b,
author={Eades, P. and S. Whitesides},
title={Drawing graphs in two Layers},
journal={Theoretical Computer Science 131},
year={1994},
pages={361-374}
}
@article{EW94a,
author={Eades, P. and N.C. Wormald},
title={Edge crossings in drawings of bipartite graphs},
journal={Algorithmica},
volume={10},
year={1994},
pages={379--403}
}
@article{War77
, author =      "J. Warfield"
, title =       "Crossing Theory and Hierarchy Mapping"
, journal =     "IEEE Trans. Syst. Man Cybern."
, volume =      "SMC-7"
, number =      7
, year =        1977
, pages =       "502--523"
}
@article{EK86
, author =      "P. Eades and D. Kelly"
, title =       "Heuristics for Reducing Crossings in 2-Layered Networks"
, journal =     "Ars Combin."
, volume =      "21.A"
, year =        1986
, pages =       "89--98"
}
@inproceedings{Dre94,
author={Dresbach, S.},
title={A New Heuristic Layout Algorithm for {DAG}s},
editor={U. Derigs and A. Bachem \& A. Drexl},
booktitle={Operations Research Proceedings 1994},
year={1994},
publisher={Springer Verlag, Berlin},
pages={121--126}
}

@misc{Dre95,
author={Dresbach, S.},
note={Personal communication},
year={1995}
}
@article{Cat95,
author={Catarci, C.},
title={The Assignment Heuristic for Crossing Reduction},
journal={IEEE Transactions on Systems, Man, and Cybernetics},
volume={25}, 
number={3},
year={1995}
}
@article{VML96,
author={Valls, V. and R. Marti and P. Lino},
title={A Branch and Bound Algorithm for Minimizing the Number of Crossing Arcs in Bipartite Graphs},
journal={Journal of Operational Research},
volume={90},
year={1996},
pages={303--319}
}
@ARTICLE{GJR85,
AUTHOR= {Gr{\"o}tschel, M. and M. J{\"u}nger and G. Reinelt},
TITLE={Facets of the linear ordering polytope},
JOURNAL={Mathematical Programming},
VOLUME={33},
YEAR={1985},
PAGES={43--60}
}
@ARTICLE{GJR84a,
AUTHOR= {Gr{\"o}tschel, M. and M. J{\"u}nger and G. Reinelt},
TITLE={A cutting plane algorithm for the linear ordering problem},
YEAR={1984},
JOURNAL={Operations Research},
VOLUME={32},
PAGES={1195--1220}
}
@ARTICLE{GJR84b,
AUTHOR= {Gr{\"o}tschel, M. and M. J{\"u}nger and G. Reinelt},
TITLE={Optimal triangulation of large real world input-output matrices},
JOURNAL={Statistische Hefte},
VOLUME={25},
YEAR={1984},
PAGES={261--295}
}
@manual{CPLEX,
title={Using the CPLEX callable library and the CPLEX mixed integer library},
organization={CPLEX Optimization Inc.},
year={1993}
}
@book{Knu93,
author={Knuth, D.E.},
title={The Stanford GraphBase: A Platform for Combinatorial Computing},
publisher={ACM Press, Addison-Wesley Publishing Company},
year={1993},
address={New York}
}