How many movies have Günther Lüders and Walter Zerlett-Olfenius collaborated on?

They have worked on 3 movies together! Their first movie together was Spiel an Bord (1936) while their highest rated movie together was Geheimakte W.B. 1 (1942). They have not worked together since Geheimakte W.B. 1 (1942). They are most known for their drama films together.