Nordostrundingen C 501 map sheet, Northeast Greenland
National Geospatial-Intelligence Agency (NGA), U.S. Army Map Service
<a rel="nofollow" class="external free" href="http://www.pgc.umn.edu/maps/arctic/id/GRL_REF-MT0503-067">http://www.pgc.umn.edu/maps/arctic/id/GRL_REF-MT0503-067</a>