@misc{indiciae124ef52da8aa,
  title = {I Zw 1 - A variable compact galaxy},
  author = {Barrett, J. W. and Shen, B. S. P. and Usher, P. D.},
  year = {1971},
  url = {https://ntrs.nasa.gov/citations/19710045925},
  note = {Source identifier: 19710045925}
}