United States. Department of the Treasury. "Public Health Service Announcement, December 28, 1938," in United States. Department of the Treasury. "Volume 25," Press Releases of the United States Department of the Treasury (October 18, 1938 - January 12, 1939) : 405-409. https://fraser.stlouisfed.org/title/6111/item/586867/toc/567479 , accessed on April 26, 2024.