Wikipedia:Dewey Decimal System/52

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Dewey Decimal System > 5 Natural Sciences and Mathematics > 52 Astronomy and Allied Sciences

520 Astronomy and Allied Sciences

521 Celestial mechanics

522 Techniques, equipment, materials

523 Specific celestial bodies and phenomena

524 Not Used

525 Earth (Astronomical geography)

526 Mathematical geography

527 Celestial navigation

528 Ephemerides

529 Chronology