@misc{indiciaeb3cb97eb5461,
  title = {Surface density of quasars in two high-latitude fields},
  author = {Usher, P. D. and Green, R. F. and Huang, K. L. and Warnock, A., III},
  year = {1983},
  url = {https://ntrs.nasa.gov/citations/19850031178},
  note = {Source identifier: 19850031178}
}