United States. Department of the Treasury. "Coast Guard Ends Ice Patrol in Trans-Atlantic Steamship Lanes, July 23, 1938," in United States. Department of the Treasury. "Volume 24," Press Releases of the United States Department of the Treasury (July 15, 1938 - October 17, 1938) : 50-52. https://fraser.stlouisfed.org/title/6111/item/586865/toc/567304 , accessed on April 25, 2024.