1. The diagnosis of art: Durer's squint – and Shakespeare's?
2. Batrum G, Grass G Albrecht Dürer and His Legacy: The Drawings show that his father had straight eyes and that his mother was affected by a divergent squint which is visible in a portrait of Dürer’s mother(charcoal on paper)
3. Campbell Hutchison J. Albrecht Dürer: A Biography. New Jersey: Princeton University Press; 1990: 1–306.
4. Goldschneider Fünfhundert Selbstportraits Wenen 1936