http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Telescope mounts M21 and M23; panoramic telescopes M5A3 and M12A2; range quadrant M4; elbow telescope M16; and instrument light M5
57 pages : illustrations, diagrams ; 23 cm.
War Department technical manual ; no. 9-1551