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.
Joconde
"La Joconde" is the French name of the Mona Lisa, which like about half of the collections of the Louvre, is included in the database, as one of 295 items by (42 including 6 paintings), after, or connected with Leonardo da Vinci. By November 2012, Joconde contained over 475,000 object listings online and over 290,000 with images, from 366 collections in France, including 209,350 drawings, 63,547 paintings, 34,561 prints, 34,102 sculptures or 16,631 costumes and their accessories and is still expanding.