Federal Reserve Bank of Cleveland. "Changing Fortunes of Bituminous Coal (4) Looking Toward the Future," in Federal Reserve Bank of Cleveland. "November 1956," Economic Review (Federal Reserve Bank of Cleveland) (November 1956) : 1-7. https://fraser.stlouisfed.org/title/1328/item/4165/toc/55063 , accessed on March 28, 2024.