Mode of access: Internet from the USGS web site. Address as of 4/10/08: http://pubs.usgs.gov/sim/2005/2906/SIM2906.pdf; current access via PURL. System requirements: PC with Internet access and ability (e.g. Adobe Reader) to handle 2.4 MB .pdf file.
At head of title: Astrogeology Research Program. Title from HTML index page (viewed on April 17, 2007). Includes text, location map, and diagram. Relief shown by contours and shading.