How many movies have Julie Gregg and Mario Puzo collaborated on?

They have worked on 3 movies together! Their first movie together was The Godfather (1972) while their highest rated movie together was The Godfather 1901–1959: The Complete Epic (1981). They have not worked together since The Godfather 1901–1959: The Complete Epic (1981). They are most known for their drama films together.