How many movies have Günther Heller and Kurt Bülau collaborated on?

They have worked on 3 movies together! Their first movie together was Schoolgirl Report Part 2: What Keeps Parents Awake at Night (1971) and was their highest rated movie together. They have not worked together since Schoolgirl Report Part 11: Trying Beats Studying (1977). They are most known for their drama films together.