Conditions in the Copper Mines of Michigan: Hearings Before a Subcommittee of the Committee on Mines and Mining, House of Representatives, Sixty-third Congress, Second Session, Pursuant to H. Res. 387, a Resolution Authorizing and Directing the Committee on Mines and Mining to Make an Investigation of Conditions in the Copper Mines of Michigan, Volumes 4-7
Jan 1914 ยท U.S. Government Printing Office