How many movies have Douglas J. White and Francisco X. Pérez collaborated on?

They have worked on 4 movies together! Their first movie together was Evilspeak (1981) while their highest rated movie together was The Sword and the Sorcerer (1982). They have not worked together since Metalstorm: The Destruction of Jared-Syn (1983). They are most known for their science fiction films together.