21. Coal mines and mining. Inspections and investigations in coal mines, hearings before subcommittee, 76th Congress, 3d session, on S. 2420, relating to certain inspections and investigations in coal mines for purpose of obtaining information relating to health and safety conditions, accidents, and occupational diseases therein, May 16-June 14, 1940. Bookmark Corporate/Agency Authors: Mines and Mining Committee, House and Congress Publisher: Mines and Mining Committee, House Date: 1940 SuDoc number: Y 4.M 66/1:C 63/3