%0 Government Document %0 Online %0 Book %A Kingery, D. S. (Donald Samuel) %A Dornenburg, D. D. %I United States Department of the Interior, Bureau of Mines %D 1957 %C Washington, D.C. %G English %B Report of investigations (United States. Bureau of Mines) ; %T Effectiveness of bleeder entries in ventilating pillared areas of bituminous-coal mines %U https://purl.fdlp.gov/GPO/gpo91532