How many movies have Christel Orthmann and Ralf Gregan collaborated on?

They have worked on 5 movies together! Their first movie together was 5 Bed Bunnies on the Loose (1972) while their highest rated movie together was Heute hau'n wir auf die Pauke (1972). They have not worked together since Cold Blood (1975). They are most known for their comedy films together.