How many movies have Gillian Hawser and Yana Stoyanova collaborated on?

They have worked on 9 movies together! Their first movie together was Boogeyman 3 (2008) while their highest rated movie together was I Spit on Your Grave 2 (2013). They have not worked together since I Spit on Your Grave 2 (2013). They are most known for their horror films together.