- Manuscripts, French1
- Manuscripts, Hebrew1
- Manuscripts, Italian1
- Manuscripts, Latin (Medieval and modern)16
- Manuscripts, Medieval23
- Manuscripts, Portuguese1
- Manuscripts, Renaissance12
- Manuscripts, Yiddish2
- Maria Anna Josefa, Queen, consort of John V, King of Portugal, 1683-17541
- Massachusetts--Boston13
- Massachusetts--Wellesley1
- Medicine1
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- Metal clasps1
- Michigan--Kalamazoo2
- Missals1
- Missing leaves1
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- Monastic and religious life3
- Monastic and religious life of women1