Isleworth Mona Lisa
According to Leonardo's early biographer Giorgio Vasari, Leonardo had started to paint "Mona Lisa" in 1503, but "left it unfinished". However, a fully finished painting of a "certain Florentine lady" surfaced again in 1517, shortly before Leonardo's death and in his private possession. The latter painting almost certainly is the one that now hangs in the Louvre. Based on this contradiction, supporters of the authenticity of the "Isleworth Mona Lisa" claim it is the unfinished "Mona Lisa", made at least partially by Leonardo, and the Louvre "Mona Lisa" a later version of it, made by Leonardo for his own use.
Portrait of Paulette Jourdain
Portrait of Paulette Jourdain is a 1919 oil painting by Italian painter Amedeo Modigliani. It was in the personal collection of A. Alfred Taubman. The painting was sold at auction by Sotheby's in November 2015 for $42.8 million. One of Modigliani's largest works, it shows Cubist influences and references the "Mona Lisa".