Classification
520 - Astronomy & allied sciences
554
500 - Natural sciences & mathematics
235
600 - Technology
122
523 - Specific celestial bodies & phenomena
114
530 - Physics
41
620 - Engineering & allied operations
21
621 - Applied physics
16
629 - Other branches of engineering
15
539 - Modern physics
13
000 - Computer science, information & general works
11
333 - Economics of land & energy
11
001 - Knowledge
10
300 - Social sciences
9
617 - Surgery & related medical specialties
9
006 - Special computer methods
8
576 - Genetics & evolution
8
610 - Medicine & health
8
700 - The arts; fine & decorative arts
8
330 - Economics
7
509 - Historical, geographic & persons treatment
7
770 - Photography, photographs & computer art
7
900 - History & geography
7
004 - Data processing & computer science
6
005 - Computer programming, programs & data
6
522 - Techniques, equipment & materials
6
658 - General management
6
320 - Political science
5
501 - Philosophy & theory
5
519 - Probabilities & applied mathematics
5
550 - Earth sciences
5
820 - English & Old English literatures
5
003 - Systems
4
510 - Mathematics
4
515 - Analysis
4
537 - Electricity & electronics
4
570 - Life sciences; biology
4
650 - Management & auxiliary services
4
681 - Precision instruments & other devices
4
910 - Geography & travel
4
040 - [Unassigned]
3
302 - Social interaction
3
363 - Other social problems & services
3
535 - Light & infrared & ultraviolet phenomena
3
616 - Diseases
3
680 - Manufacture for specific uses
3
771 - Techniques, equipment & materials
3
011 - Bibliographies
2
020 - Library & information sciences
2
158 - Applied psychology
2
303 - Social processes
2
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