How many movies have Tony Ching Siu-Tung and Wong Kwan-Yuen collaborated on?

They have worked on 3 movies together! Their first movie together was The Eighth Happiness (1988) while their highest rated movie together was All About Ah-Long (1989). They have not worked together since The Fun, the Luck & the Tycoon (1990). They are most known for their comedy films together.