Sulpy, Doug & Schweighhardt, Ray, Drugs, Divorce and a Slipping Image: The Complete, Unauthorized Story of the Beatles Get Back Sessions (The_910 Publishing, 2007) ISBN978-0-9643869-8-3
Sulpy, Doug & Schweighhardt, Ray, Get Back: The Unauthorized Chronicle of the Beatles Let It Be Disaster (St. Martin's Press, 1997) ISBN0-312-15534-4