How many movies have Cai Văn Mỹ and Nguyễn Quý Viện collaborated on?

They have worked on 6 movies together! Their first movie together was Cards on the Table: The Gunshot on the Highland (1983) and was their highest rated movie together. They have not worked together since Cards on the Table: High Pressure and the Freshet (1987). They are most known for their thriller films together.