United States. Department of the Treasury. "U.S. And U.S.S.R. Begin Negotiating Income Tax Treaty, December 4, 1972," in United States. Department of the Treasury. "Volume 181," Press Releases of the United States Department of the Treasury (October 2, 1972 - December 29, 1972) : 412-413. https://fraser.stlouisfed.org/title/6111/item/587024/toc/542852 , accessed on June 25, 2024.