@conference{9237,
  author = {Mitchell Begelman},
  title = {Physics of the central engine},
  year = {1989},
  journal = {unknown},
  publisher = {Kluwer Academic Publishers, Dordrecht},
  address = {Santa Cruz, California},
  url = {http://adsabs.harvard.edu/full/1989IAUS..134..141B},
}