MacCallum, Spencer Heath (December 19, 2003). "Looking Back and Forward". Walter Block's Autobiography Archive. LewRockwell.com. Archived from the original on September 27, 2012.
MacCallum, Spencer Heath (December 19, 2003). "Looking Back and Forward". Walter Block's Autobiography Archive. LewRockwell.com. Archived from the original on September 27, 2012.