Board of Governors of the Federal Reserve System (U.S.), 1935- and Federal Reserve Board, 1914-1935. "Indexes of Factory Employment and Pay Rolls," in Board of Governors of the Federal Reserve System (U.S.), 1935- and Federal Reserve Board, 1914-1935. "April 1930," Federal Reserve Bulletin (April 1930) : 33-33. https://fraser.stlouisfed.org/title/62/item/20700/toc/232129 , accessed on April 26, 2024.