@article{2120,
  author = {Mitchell Begelman and A. Fabian and M. Rees},
  title = {Implications of very rapid TeV variability in blazars},
  year = {2008},
  journal = {Monthly Notices of the Royal Astronomical Society: Letters},
  volume = {384},
  pages = {L19 - L23},
  month = {02/2008},
  issn = {1745-3925},
  doi = {10.1111/j.1745-3933.2007.00413.x},
}