United States. Department of the Treasury. "Treasury offers $3 billion In June Tax Bills, October 10, 1968," in United States. Department of the Treasury. "Volume 163," Press Releases of the United States Department of the Treasury (October 1, 1968 - January 20, 1969) : 56-58. https://fraser.stlouisfed.org/title/6111/item/587006/toc/541181 , accessed on June 21, 2024.