sentences:  Wildenstein Index Number
  
  A Wildenstein Index Number refers to an item in a numerical system published in catalogues by Daniel Wildenstein, a scholar of Impressionism, who published catalogues raisonnés of artists such as Claude Monet, Édouard Manet and Paul Gauguin through his family business, Wildenstein & Company.In these catalogues, each painting by an artist was assigned a unique number.