Kroppy, Joseph F. and Witkowski, Edward. Letter to Marriner Eccles, Box 84, Folder 14, Item 2, Marriner S. Eccles Papers. https://fraser.stlouisfed.org/scribd/?item_id=464524&filepath=/files/docs/historical/eccles/084_14_0002.pdf&start_page=1, accessed on September 20, 2017.
Letter from Edward Witkowski and Joseph Kroppy inviting Eccles to be a guest speaker at a banquet hosted by the Manhattan Society in honor of M.S. Szymczak.
- Banks and banking
- Board of Governors of the Federal Reserve System (U.S.), 1935-
- Federal Reserve Board, 1914-1935