Alfraganus
| Author(s) | Title | Reference | |
|---|---|---|---|
| F.S. Taylor | The Sphere of Sacrobosco and Its Commentators, by Lynn Thorndike | 20/, p. 86 | |
| J.D. North | Campanus of Novara and Medieval Planetary Theory: Theorica planetarum, by Francis S. Benjamin Jr., G. J. Toomer | 42/3, p. 272 |