How many movies have Günter Sonnenberg and Hans Hardt-Hardtloff acted in together?

They have worked on 4 movies together! Their first movie together was Carl von Ossietzky (1963) while their highest rated movie together was Entlassen auf Bewährung (1965). They have not worked together since Verwandte und Bekannte (1971). They are most known for their drama films together.