@article{UNVienna Convention on the Law of Treaties,
  author = {{United Nations}},
  title = {Vienna Convention on the Law of Treaties},
  year = {1969},
  month = may,
  venue = {New York},
  journal = {Treaty Series},
  volume = {1155},
  pages = {331},
  notes = {Entry into force 27 January 1980},
  month_numeric = {5}
}