@Misc{Brown1998,revisedFebruary2001,
author="Brown, J.
and Ferrians Jr., O. J.
and Heginbottom, J. A.
and Melnikov, E. S.",
title="Circum-arctic map of permafrost and ground ice conditions",
year="1998, revised February 2001",
publisher="National Snow and Ice Data Center. Digital media",
address="Boulder, CO"
}