He was known for his readymades such as "L.H.O.O.Q.", a copy of the "Mona Lisa" with a penciled-in mustache & beard
The readymade involves taking mundane, often utilitarian 
objects not ... As was the case with a number of his readymades, Duchamp made 
multiple... [DOC] [TLE] LHOOQ, Marcel Duchamp (1919) - The Guardian [PAR] May 26, 2001 ...