Walker IBP site and topogrid with 7 themes. These are currently in a paper/mylar version and need to be digitized. Once complete, they will be available for download here.
Walker. 1977. The Analysis of the Effectiveness of a Television Scanning Densitometer for Indicating Geobotanical Features in an ice-Wedge Polygon Complex at Barrow, Alaska. M.A. University of Colorado, Boulder.