@article{CofGroups-AFP,
author = {Bart Kastermans},
title = {An Example of a Cofinitary Group in Isabelle/HOL},
journal = {Archive of Formal Proofs},
month = {August},
year = {2009},
note = {\url{https://isa-afp.org/entries/CofGroups.html},
Formal proof development},
ISSN = {2150-914x},
}