Hatfield 1997, pp. 337–343. Hatfield, Mark O.; with the Senate Historical Office (1997). Vice Presidents of the United States, 1789–1993. Washington: U.S. Government Printing Office. pp. 337–43. Reprint on U.S. Senate website. – Introduction by Mark O. Hatfield (for full citation from the Senate website, see printer option at the bottom of the webpage).