@TechReport{tgc08,
  author = {Ebbe Elsborg and Thomas T. Hildebrandt and Davide Sangiorgi},
  title = {Type {S}ystems for {B}igraphs},
  institution = {The IT University of Copenhagen},
  year = {2008},
  number = {110},
  address = {Rued Langgaards Vej 7, DK-2300 Copenhagen S, Denmark},
  month = {October},
  note = {Full version of the TGC'08 paper}
}