Visitors view Gerhard Richter's 'Domplatz, Mailand (Cathedral Square, Milan)' (L), oil on canvas and executed in 1968, estimated between $30-40 million, and Francis Bacon's 'Study for Portrait of P.L.' dated 1962 and estimated $30-40 million, during a preview of Sotheby's May 14 Contemporary Art Evening Auction at Sotheby's in New York, May 3, 2013. REUTERS/Mike Segar (UNITED STATES - Tags: ENTERTAINMENT)