Rybicki, Elizabeth; Greene, Michael (October 10, 2019). "The Impeachment Process in the House of Representatives". CRS Report for Congress. Washington, D.C.: Congressional Research Service, Library of Congress. pp. 5–7. R45769. Archived from the original on January 22, 2020. Retrieved November 7, 2019.
"The Smoking Gun Tape"(Transcript of the recording of a meeting between President Nixon and H. R. Haldeman). Watergate.info website. June 23, 1972. Archived from the original on May 1, 2012. Retrieved January 17, 2007.
Rybicki, Elizabeth; Greene, Michael (October 10, 2019). "The Impeachment Process in the House of Representatives". CRS Report for Congress. Washington, D.C.: Congressional Research Service, Library of Congress. pp. 5–7. R45769. Archived from the original on January 22, 2020. Retrieved November 7, 2019.
"The Smoking Gun Tape"(Transcript of the recording of a meeting between President Nixon and H. R. Haldeman). Watergate.info website. June 23, 1972. Archived from the original on May 1, 2012. Retrieved January 17, 2007.