@misc{indiciae9ea15692a836,
  title = {The Cygnus 'superbubble' - A supernova explosion in a tenuous intercloud medium},
  author = {Higdon, J. C.},
  year = {1981},
  url = {https://ntrs.nasa.gov/citations/19810044757},
  note = {Source identifier: 19810044757}
}