These are the source references for Episode 1 of Rachel Maddow's Bag Man podcast, which you can listen to here, or through your preferred podcasting service.
Books:
Witcover, Jules. “Very Strange Bedfellows: The Short and Unhappy Marriage of Richard Nixon and Spiro Agnew”, PublicAffairs, 2008
Nixon, Richard. “RN: The Memoirs of Richard Nixon”, Simon & Schuster, 1990
Cohen, Richard and Witcover, Jules. “A Heartbeat Away”, Viking Press, 1974
Agnew, Spiro T. “Go Quietly … Or Else”, William Morrow, 1980
London, Martin. “The Client Decides: A Litigator's Life: Jackie Onassis, Vice President Spiro Agnew, Donald Trump, Roy Cohn, and More”, Eastlake Press, 2017
Coffey, Justin. “Spiro Agnew and The Rise of the Republican Right”, Praeger, 2015
Articles:
“Agnew Calls U.S. Imperiled By Irresponsible Dissenters”, The Baltimore Sun Newspaper (September 29, 1968)
“HHH Has Been a Softy, Agnew Says”, Detroit Free Press Newspaper, (September 11, 1968)
“Ford Demands Negro Apologize To Agnew”, The Tampa Tribune Newspaper (July 23, 1971)
“Agnew Unintentionally Triggers Renewed Round of Anti-Semitism”, The Washington Post, December 30, 1969, ((Courtesy of The Weisberg Collection. Hood College. Frederick, MD, USA)
“Closing In on Agnew: The Prosecutors’ Story” by Aaron Latham. “New York Magazine” (November 26, 1973)
Archival Material:
“My Kind of Man/Ted Agnew Is.” Spiro T. Agnew 1966 Gubernatorial campaign radio ads (courtesy of the Richard Nixon Presidential Library)
NBC News Special Coverage of 1968 Republican National Convention (August 8, 1968)
1968 Hubert Humphrey “Laughter” Campaign Ad (Source: Museum of the Moving Image)
NBC News Coverage of 1968 Presidential Campaign (Courtesy: NBC News Archives)
NBC Nightly News (September 24, 1968)
NBC Nightly News (January 3, 1971)
NBC News Special Report (November 13, 1969); Agnew speech on the media (Transcript)
NBC Nightly News (November 14, 1969)
NBC Nightly News (November 21, 1969)
NBC News Special Report, Senate Watergate Hearings (May 23, 1973)
NBC Nightly News (May 13, 1973)
NBC News Special Report, Vice President Agnew Speech in Los Angeles (September 29, 1973)