@misc{indiciae572bd1757983,
  title = {Extraterrestrial cause for the Cretaceous-Tertiary extinction},
  author = {Alvarez, L. W. and Alvarez, W. and Asaro, F. and Michel, H. V.},
  year = {1980},
  url = {https://ntrs.nasa.gov/citations/19800051929},
  note = {Source identifier: 19800051929}
}