How many movies have Håkan Westergren and Per-Olav Sivertzen-Falk collaborated on?

They have worked on 4 movies together! Their first movie together was 48 Hours to Live (1959) while their highest rated movie together was En sån strålande dag (1967). They have not worked together since Do You Believe in Swedish Sin? (1970). They are most known for their comedy films together.