@misc{indiciae10f6b4e2e934,
  title = {Astronomy},
  author = {Gunn, J. E. and Livingston, W. C. and Newkirk, G. A. and Norton, R. H. and Zirin, H.},
  year = {1968},
  url = {https://ntrs.nasa.gov/citations/19680028785},
  note = {Source identifier: 19680028785}
}