http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Effectiveness of bleeder entries in ventilating pillared areas of bituminous-coal mines
1 online resource (ii, 24 pages) : illustrations.
"Work on manuscript completed August 1956."
Report of investigations (United States. Bureau of Mines) ; 5360