How many movies have Lau Siu-Kwan and Mona Fong Yat-Wah collaborated on?

They have worked on 18 movies together! Their first movie together was Corpse Mania (1981) while their highest rated movie together was The Duel of the Century (1981). They have not worked together since Disciples of the 36th Chamber (1985). They are most known for their action films together.