- Manuscripts, Latin22
- Manuscripts, Latin (Medieval and modern)27
- Manuscripts, Medieval57
- Manuscripts, Persian12
- Manuscripts, Provençal1
- Manuscripts, Renaissance1
- Manuscripts, Spanish1
- Manuscripts, Turkish2
- Marriage (Canon law)1
- Mary, Blessed Virgin, Saint1
- Mary, Blessed Virgin, Saint, in the liturgy--Orthodox Eastern Church1
- Masorah1
- Massachusetts--Northampton1
- Massachusetts--Williamstown1
- Materia medica, Animal1
- Mathematics, Arab1
- Mathematics, Greek1
- Medicine3
- Medicine, Arab2
- Metaphysics1