United States. Department of the Treasury. "Amendment to Circular No. 667, October 21, 1941," in United States. Department of the Treasury. "Volume 38," Press Releases of the United States Department of the Treasury (October 11, 1941 - December 11, 1941) : 58-60. https://fraser.stlouisfed.org/title/6111/item/586880/toc/566197 , accessed on September 30, 2023.