Columbia subject headings:
Illustrated works.
Leonardo, da Vinci, 1452-1519--Criticism and interpretation.
Painting--Technique.
Harvard subject headings:
Illustrated works
Leonardo, da Vinci, 1452-1519--Criticism and interpretation.
Painting--Technique
Princeton subject headings:
Leonardo, da Vinci, 1452-1519--Criticism and interpretation.
Painting--Technique.