BibTeX: 
@article{Lambda_Free_RPOsAFP,
author = {Jasmin Christian Blanchette and Uwe Waldmann and Daniel Wand},
title = {Formalization of Recursive Path Orders for LambdaFree HigherOrder Terms},
journal = {Archive of Formal Proofs},
month = sep,
year = 2016,
note = {\url{http://isaafp.org/entries/Lambda_Free_RPOs.html},
Formal proof development},
ISSN = {2150914x},
}
