Author,Title,Edition,Publisher,Year,Series,Number,ISBN,ISSN,URL
United States. Bureau of Labor Statistics,Productivity trends in selected industries : indexes through 1950,,"For sale by the Supt. of Docs., U.S. Govt. Print. Off.,U.S. Dept. of Labor, Bureau of Labor Statistics",1951,Bulletin,,,,https://cir.nii.ac.jp/crid/1130000794772893824