2. University of Pennsylvania, LJS 216 Title: Sphaera mundi Author: Johannes de Sacrobosco Place: Paris Date: [between 1256 and 1270]
4. University of Pennsylvania, Ms. Coll. 591 Folder 20 Title: In libros De caelo et mundo Aristotelis Author: Thomas Aquinas Date: between 1275 and 1299.
5. Free Library of Philadelphia, Lewis E 250 Title: Treatise on the construction of an astrolabe Author: John of Seville Place: undetermined Date: 1400-1499