Encyclopedias, Almanacs, Transcripts, and Maps
- Lodovico Ferrari
- Loehr, Franklin (Davison) (1912-1988)
- Logan, Daniel (1936-)
- Logical Empiricism
- Logrunners and Chowchillas: Orthonychidae
- Lokaloka
- London Dialectical Society
- Long QT Syndrome
- Long, James A. (1898-1971)
- Long, Max Freedom (1890-1971)
- Long-QT syndrome
- Long-Tailed Titmice: Aegithalidae
- Long-Term Care
- Long-Term Care: I. Concept and Policies
- Long-Term Care: II. Nursing Homes
- Long-Term Care: III. Home Care
- Longomontanus
- Loons
- Loons
- Loons: Gaviiformes