United States. Department of the Treasury. "Bill results on April tax bills, July 16, 1970," in United States. Department of the Treasury. "Volume 169," Press Releases of the United States Department of the Treasury (May 6, 1970 - August 3, 1970) : 575-576. https://fraser.stlouisfed.org/title/6111/item/587012/toc/541849 , accessed on June 16, 2024.