Former Owner
- Lathrop C. Harper, Inc.1
- Laurentius van der Torqel1
- Libreria la Bibliofila1
- Libri, Edoardo, active 20th century1
- Loftus Bland1
- Louis César de La Baume Le Blanc1
- Louis II, Count of Flanders1
- Lucien Magne1
- Luigi Celotti1
- Léon Gruel1
- Léon Techener1
- Marguerite de Fontenay1
- Marie Ange-Toussaint Placide de Ferron1
- Marie Cleophe de Sollario1
- Marie de Albano1
- Marie-Caroline of Bourbon-Two Sicilies, Duchess of Berry1
- Marino Grimani1
- Maurice Kann1
- Mayfair Rare Books and Manuscripts1
- Middle Hill Rare Books & Manuscripts AB (Stockholm, Sweden)1