United States. Department of the Treasury. "Procurement Emergency Specifications, July 20, 1941," in United States. Department of the Treasury. "Volume 36," Press Releases of the United States Department of the Treasury (June 21, 1941 - August 12, 1941) : 283-285. https://fraser.stlouisfed.org/title/6111/item/586878/toc/560910 , accessed on May 16, 2024.