How many movies have Günther Heller and Hellmuth Haupt collaborated on?

They have worked on 4 movies together! Their first movie together was Sex in the Office (1971) while their highest rated movie together was Schoolgirl Report Part 2: What Keeps Parents Awake at Night (1971). They have not worked together since Schoolgirl Report Part 11: Trying Beats Studying (1977). They are most known for their drama films together.