BibTeX: 
@article{Sqrt_BabylonianAFP,
author = {RenĂ© Thiemann},
title = {Computing Nth Roots using the Babylonian Method},
journal = {Archive of Formal Proofs},
month = jan,
year = 2013,
note = {\url{http://isaafp.org/entries/Sqrt_Babylonian.html},
Formal proof development},
ISSN = {2150914x},
}
