BibTeX: 
@article{Girth_ChromaticAFP,
author = {Lars Noschinski},
title = {A Probabilistic Proof of the GirthChromatic Number Theorem},
journal = {Archive of Formal Proofs},
month = feb,
year = 2012,
note = {\url{http://isaafp.org/entries/Girth_Chromatic.html},
Formal proof development},
ISSN = {2150914x},
}
