Classification
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520 - Astronomy & allied sciences
10
523 - Specific celestial bodies & phenomena
2
530 - Physics
21
535 - Light & infrared & ultraviolet phenomena
1
539 - Modern physics
1
540 - Chemistry & allied sciences
51
541 - Physical chemistry
14
543 - Analytical chemistry
7
546 - Inorganic chemistry
10
547 - Organic chemistry
41
550 - Earth sciences
4
551 - Geology, hydrology & meteorology
46
553 - Economic geology
1
559 - Earth sciences of other areas
1
570 - Life sciences; biology
14
572 - Biochemistry
14
574 - [Unassigned]
5
576 - Genetics & evolution
30
577 - Ecology
6
579 - Microorganisms, fungi & algae
1
580 - Plants (Botany)
38
581 - Specific topics in natural history
21
590 - Animals (Zoology)
1
599 - Mammals
2
600 - Technology
294
601 - Philosophy & theory
10
606 - Organizations
1
607 - Education, research & related topics
2
608 - Inventions & patents
6
609 - Historical, geographic & persons treatment
4
610 - Medicine & health
179
612 - Human physiology
5
613 - Personal health & safety
5
614 - Incidence & prevention of disease
1
615 - Pharmacology & therapeutics
29
616 - Diseases
11
617 - Surgery & related medical specialties
2
620 - Engineering & allied operations
302
621 - Applied physics
164
622 - Mining & related operations
1
623 - Military & nautical engineering
6
624 - Civil engineering
6
628 - Sanitary & municipal engineering
29
629 - Other branches of engineering
75
630 - Agriculture & related technologies
76
631 - Techniques, equipment & materials
5
632 - Plant injuries, diseases & pests
17
634 - Orchards, fruits & forestry
3
639 - Hunting, fishing & conservation
1
643 - Housing & household equipment
1
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