How many movies have Erkki Poikonen and Mikko Niskanen collaborated on?

They have worked on 4 movies together! Their first movie together was Kaunis Kaarina (1955) while their highest rated movie together was Pekka ja Pätkä sammakkomiehinä (1957). They have not worked together since Kahden ladun poikki (1958). They are most known for their drama films together.