How many movies have Bas van Toor and Guus Verstraete jr. collaborated on?

They have worked on 3 movies together! Their first movie together was Bassie & Adriaan: The Poltergeist (1978) while their highest rated movie together was Bassie & Adriaan: The Secret of the Key (1978). They have not worked together since Bassie & Adriaan: The Crying Professor (1982). They are most known for their comedy films together.