Board of Governors of the Federal Reserve System (U.S.), 1935- and Federal Reserve Board, 1914-1935. "Crude Petroleum," in Board of Governors of the Federal Reserve System (U.S.), 1935- and Federal Reserve Board, 1914-1935. "September 1921," Federal Reserve Bulletin (September 1921) : 72-72. https://fraser.stlouisfed.org/title/62/item/20527/toc/392957 , accessed on April 25, 2024.