Leiden University Libraries
- Leiden University Libraries published the following 3 sources, containing a total of 26 diagrams.
- Boethius, Anicius Manlius Severinus. 1001–1100. De syllogismo categorico. Leiden: Leiden University Libraries. (2 diagrams)
- Apuleius, Lucius. 975–1025. Peri hermeneias. Leiden: Leiden University Libraries. (2 diagrams)
- Floriacensis, Abbo. 975–1025. De syllogismis categoricis. Leiden: Leiden University Libraries. (22 diagrams)