"1920-1922 Agreement between the members of District No. 13, U. M. W. of A., parties of the first part and the members of the Iowa Coal Operators' Ass'n, parties of the second part, April 1, 1920 to March 31, 1922."; "Iowa Coal Operators Association.", "United Mine Workers of America. District 13."; "Collective labor agreements--Coal mining industry--Middle West."; "[1920?]"; "

Monograph.

"; ""; "P13009"; "pec"; "United Mine Workers of America. District 13.", "Collective labor agreements--Coal mining industry--Middle West.", "Iowa Coal Operators Association."; "14256"; .