@misc{indiciae435497540bd8,
  title = {Clustering environments of BL Lac objects},
  author = {Wurtz, Ronald and Ellingson, Erica and Stocke, John T. and Yee, H. K. C.},
  year = {1993},
  url = {https://ntrs.nasa.gov/citations/19930071620},
  note = {Source identifier: 19930071620}
}