Encyclopedias, Almanacs, Transcripts, and Maps
- Plant Pigment
- Plant Viruses
- Plantcutters: Phytotomidae
- Plants, Psychic Aspects of
- Plasmids
- Plate Tectonic Theory and the Unification of the Earth Sciences
- Plato of Tivoli
- Platonic Solids
- Platonic Solids
- Playfair, Guy Lyon (1935-)
- Playing God
- Plexopathies
- Plovers and Lapwings: Charadriidae
- Plummer, George Winslow (1876-1944)
- Pluto
- Pluto
- Pluton and Plutonic Bodies
- PMIR
- Pneumatographers
- Pneumonia, Bacterial and Viral