@article{8618,
  author = {P. Schneider},
  title = {The amplification bias by gravitational lensing on observed number counts of quasars - Effects of a finite source size},
  year = {1987},
  journal = {The Astrophysical Journal},
  volume = {316},
  pages = {L7},
  month = {Jan-05-1987},
  issn = {0004-637X},
  url = {http://articles.adsabs.harvard.edu/full/1987ApJ...316L...7S},
  doi = {10.1086/184881},
}