De crepusculis et nubium ascensionibus
(lat.: a Gerardo Cremonensi, ed.: (F. Risner) F. Risnero, Opticae thesaurus: Alhazeni Arabis libri septem, nuncprimum editi; Eiusdem liber De Crepusculis et nubium ascensionibus, per Episcopios, Basileae 1572)
at Posner Memorial Collection
[posner.library.cmu.edu/Posner/books/pages.cgi?call=535_A17O_1572&layout=vol0/part0/copy0&file=0002]
[posner.library.cmu.edu/Posner/books/pages.cgi?call=535_A17O_1572&layout=vol0/part0/copy0&file=0292]

Opticae, libri septem/Kitab al-Manazir/Manadhir
(lat.: E.C. Witelo, ed.: (F. Risner) F. Risnero, Opticae thesaurus: Alhazeni Arabis libri septem, nuncprimum editi; Eiusdem liber De Crepusculis et nubium ascensionibus, per Episcopios, Basileae 1572)
at Posner Memorial Collection
[posner.library.cmu.edu/Posner/books/pages.cgi?call=535_A17O_1572&layout=vol0/part0/copy0&file=0002]
[posner.library.cmu.edu/Posner/books/pages.cgi?call=535_A17O_1572&layout=vol0/part0/copy0&file=0010]