La Divina Commedia di Dante, Santa Maria del Fiore, Firenze, Domenico di Michelino, mid-1460s fresco
The Cambridge Companion to Dante by 
The Dante Encyclopedia by 
Dante and the Origins of Italian Literary Culture by 
Petrarch and Dante: anti-Dantism, metaphysics, tradition by 
The Divine Comedy of Dante Alighieri by 
The Monarchia Controversy by 
Bodleian Library. Ms. Holkham misc 48, p. 28
Inferno, Canto XIX.
Virgil stands beside Dante, who listens to Nicholas III among the simonists.
British Library. Yates Thompson 36, f. 150
Paradiso, Canto XII.
Dante and Beatrice before Bonaventure, who is standing in the Heaven of the Sun, while on the right, Dominic is preaching to a group of heathens.