How many movies have Fred Zenker and Walter Boos collaborated on?

They have worked on 3 movies together! Their first movie together was Schoolgirl Report Part 5: What All Parents Should Know (1973) while their highest rated movie together was Three Swedes on the Reeperbahn (1980). They have not worked together since Three Swedes on the Reeperbahn (1980). They are most known for their comedy films together.