BibTeX: 
@article{Liouville_NumbersAFP,
author = {Manuel Eberl},
title = {Liouville numbers},
journal = {Archive of Formal Proofs},
month = dec,
year = 2015,
note = {\url{http://isaafp.org/entries/Liouville_Numbers.shtml},
Formal proof development},
ISSN = {2150914x},
}
