Long alphabetical list of links to Leonardo paintings and drawings.

Museum of Science, Boston.

The University of Minnesota.

Museo Nazionale della Scienza - Milan.

Sketch archive - quite extensive.

The Leonardo Museum in Vinci - interesting models.

Art54 - Art and poster sales

Leonardo - Jean-Claude Frere.  Terrail 1995.

Leonardo, Psychoanalysis and Art History - Bradley I. Collins.  Northwestern University Press 1997.

The Notebooks of Leonardo da Vinci - Irma A. Richter.  Oxford University Press 1952.