How many movies have Fritz Koselka and Lilian Belmont collaborated on?

They have worked on 3 movies together! Their first movie together was Ich bitte um Vollmacht (1944) while their highest rated movie together was Jetzt schlägt's 13 (1950). They have not worked together since Jetzt schlägt's 13 (1950). They are most known for their comedy films together.