@inproceedings{Lavignac:1999s3,
  author = "Lavignac, S.",
  title = "{Heterotic Type I Duality in Four Dimensions in the Presence of Anomalous U(1)'s}",
  doi = "10.22323/1.002.0018",
  booktitle = "Proceedings of European Network on Physics beyond the Standard Model {\textemdash} PoS(trieste99)",
  year = 1999,
  volume = "002",
  pages = "018"
}