http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Issued in quadrangles 1⁰ of latitude by 1⁰30' of longitude.
Relief shown variously by contours, form lines, and shading.
Each sheet includes "Glossary," "Location diagram," and "Reliability diagram."
Some sheets have through route maps of cities on versos.
Accompanied by index map on sheet 27 x 50 cm.
Series (Standard map series designation system) ; G504