Search for: [References = "4. Brown J., Ferrians Jr. O.J., Heginbottom J.A., Melnikov E.S., 1998, revised February 2001, Circum\-arctic Map of Permafrost and Ground Ice Conditions, Boulder, CO\: National Snow and Ice Data Center. Digital media. http\:\/\/nsidc.org\/data\/docs\/fgdc\/ggd318_map_circumarctic\/#5. \(7.09.2015\)"]