00766cam a22002531 4500 e 31000714 DLC 20260227111221.0 820225s1931 dcua 000 0 eng e 31000714 (OCoLC)29093755 DLC MnU OCoLC DLC premarc LC1045 .A25 no. 41b United States. Federal Board for Vocational Education. Coal-mine ventilation, Revised ed. [Washington, U.S. Govt. print. off., 1931]. xi, 92 p. illus. 23 cm. Mine ventilation. Virgin, Robert Zerubabel. Callen, Alfred Copeland, 1888- Rice, George S. (George Samuel), 1866-1950. 21128 21128