@inproceedings{webb1981independence,
  title = "An independence theorem for automorphisms of torsion-free groups",
  author = "Webb, UHM",
  year = "1981",
  booktitle = "Mathematical Proceedings of the Cambridge Philosophical Society",
  number = "3",
  organization = "Cambridge University Press",
  pages = "403--409",
  volume = "90",
}