Schaber, Gerald G.; John F. McCauley (1980). Geologic Map of the Tolstoj (H-8) Quadrangle of Mercury(PDF). U.S. Geological Survey. USGS Miscellaneous Investigations Series Map I–1199, as part of the Atlas of Mercury, 1:5,000,000 Geologic Series. Diakses tanggal 2007-11-12.
Schaber, Gerald G.; John F. McCauley (1980). Geologic Map of the Tolstoj (H-8) Quadrangle of Mercury(PDF). U.S. Geological Survey. USGS Miscellaneous Investigations Series Map I–1199, as part of the Atlas of Mercury, 1:5,000,000 Geologic Series. Diakses tanggal 2007-11-12.