A personal testimony by
found on page 271 of the Czech book "3x18 (portraits and insights)",
authored by Arnošt Lustig with František Cinger (who submitted questions to the subject and interviewed him for this book), published by Nakladatelství Andrej Štastný,
Lustig writes that Heller told him so in New York at an evening party to which he was brought by film director Miloš Forman ("Black Peter", "Loves of a Blond", "One Flew Over the Cuckoo's Nest", "Amadeus") and Ivan Passer (director of"Intimate Lighting" - his second film as a director and his last before going to work in America after the Warsaw Pact military invasion of Czechoslovakia in 1968 - and "Creator", starring Peter O'Toole, Mariel Hemingway, US, 1985, etc. Ivan Passer also scripted three of Miloš Forman's films).