BibTeX: 
@article{Closest_Pair_PointsAFP,
author = {Martin Rau and Tobias Nipkow},
title = {Closest Pair of Points Algorithms},
journal = {Archive of Formal Proofs},
month = jan,
year = 2020,
note = {\url{https://isaafp.org/entries/Closest_Pair_Points.html},
Formal proof development},
ISSN = {2150914x},
}
