While researching for the first chapter of my dissertation, I became aware that there was a lot of information in books on Leonardo da Vinci that had little or no relevance to the pieces I was looking at.
The basis for the first chapter was on a piece called St John the Baptist which has since been destroyed making it hard to find large chunks of information. In order to overcome this problem I had to expand my search to psychoanalysis to find books with any information on the piece.
These books had theories of why they thought the artist painted in the way he did, and this became an important part to discuss within the chapter. It also meant that I found more information about the painting techniques as they would use this as a way of deterring the sexuality of the figure.