@inproceedings{SpoenemannFvH+09,
  author = {Miro Sp{\"o}nemann and Hauke Fuhrmann and Reinhard von Hanxleden and Petra Mutzel},
  title = {Port Constraints in Hierarchical Layout of Data Flow Diagrams},
  booktitle = {Proceedings of the 17th International Symposium on Graph Drawing (GD '09)},
  publisher = {Springer},
  series = {LNCS},
  volume = {5849},
  pages = {135--146},
  year = {2010},
  doi = {10.1007/978-3-642-11805-0},
  pdf = {gd09.pdf},
  urltalk = {gd09-talk.pdf},
  htmlnote = {The \href{http://www.springerlink.com/content/r175p132n715wjw1}{original publication} is available at \href{http://www.springerlink.com}{www.springerlink.com}.},
}