How many movies have Renato Doria and Riccardo Billi collaborated on?

They have worked on 5 movies together! Their first movie together was Avventura al motel (1963) while their highest rated movie together was Snow White and 7 Dwarfs (1995). They have not worked together since Hamlet: For the Love of Ophelia (1995). They are most known for their comedy films together.