@misc{indiciae68208aeba1a9,
  title = {Exact hierarchical clustering in one dimension},
  author = {Williams, B. G. and Heavens, A. F. and Peacock, J. A. and Shandarin, S. F.},
  year = {1991},
  url = {https://ntrs.nasa.gov/citations/19910053075},
  note = {Source identifier: 19910053075}
}