@article{bdnsz-pttp-09,
author = {Pankaj Agarwal and Sergey Bereg and Ovidiu Daescu and Haim Kaplan and Simeon Ntafos and Micha Sharir and Binhai Zhu},
title = {Guarding a Terrain by Two Watchtowers},
journal = {Algorithmica},
year = {2009},
note = {to appear},
url = {http://dx.doi.org/10.1007/s00453-008-9270-3}
}