In Fukuda et al. (eds) "Proceedings of ICMS 2010", Springer LNCS vol. 6327,
2010.
This is superseded by the corresponding full paper
@INPROCEEDINGS{harrison-picka,
author = "John Harrison",
title = "A formal proof of Pick's theorem
(extended abstract)",
editor = "Komei Fukuda and Joris van der Hoeven and
Michael Joswig and Nobuki Takayama",
booktitle = "Proceedings of ICMS 2010, the Third International
Congress on Mathematical Software",
address = "Kobe, Japan",
date = "September 2010",
publisher = "Springer-Verlag",
series = "Lecture Notes in Computer Science",
volume = 6327,
year = 2010,
pages = "152--154"}