Sentence:  Austrian director Gustav Deutsch complicates this witty, deceptively simple formula with a wealth of <WSD>found footage</WSD> (material shot by others for other purposes) borrowed from film archives from around the world. 
Meaning of the word marked with <WSD> tags:  Misplaced, forgotten, archived, or privately-owned motion picture recordings which document past events and which are subsequently rediscovered and made available for public viewing.