Thema Subject Categories 1.4

Previous versions of Thema are still available 1.3 1.2 1.1 1.0.

Browse the Thema subject categories hierarchy, or search for a specific term within the hierarchy.

See the search hints below.

Notation Category heading Add Mod ?
P Mathematics and Science
Use all P* codes for: mostly academic, technical and specialist titles and some general adult works. Qualifiers are mostly not required with P* codes. DO NOT USE: code ‘P’ itself, but select specific categories from section P*.
Prefer: WN* codes for general interest adult titles where appropriate
PG Astronomy, space and time
See also: TTD* Space science and its subcategories
PGC Theoretical and mathematical astronomy
See also: PHVB Astrophysics
PGG Astronomical observation: observatories, equipment and methods
See also: WNX Popular astronomy and space
PGK Cosmology and the universe
PGM Galaxies and stars
Class here: exoplanets, extrasolar planets
PGS Solar system: the Sun and planets
Class here: the Moons of the different planets
PGT Astronomical charts and atlases
PGZ Time (chronology), time systems and standards

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