Classification
630 - Agriculture & related technologies
142
580 - Plants (Botany)
55
600 - Technology
52
620 - Engineering & allied operations
52
610 - Medicine & health
39
330 - Economics
37
333 - Economics of land & energy
34
700 - The arts; fine & decorative arts
28
581 - Specific topics in natural history
27
363 - Other social problems & services
25
571 - Physiology & related subjects
17
551 - Geology, hydrology & meteorology
15
320 - Political science
14
500 - Natural sciences & mathematics
10
631 - Techniques, equipment & materials
9
338 - Production
8
414 - Phonology & phonetics
8
540 - Chemistry & allied sciences
7
660 - Chemical engineering
7
900 - History & geography
7
300 - Social sciences
6
340 - Law
6
577 - Ecology
6
000 - Computer science, information & general works
5
140 - Specific philosophical schools
5
579 - Microorganisms, fungi & algae
5
910 - Geography & travel
5
170 - Ethics
4
570 - Life sciences; biology
4
576 - Genetics & evolution
4
592 - Invertebrates
4
658 - General management
4
664 - Food technology
4
004 - Data processing & computer science
3
100 - Philosophy & psychology
3
304 - Factors affecting social behavior
3
361 - Social problems & social welfare in general
3
400 - Language
3
003 - Systems
2
006 - Special computer methods
2
200 - Religion
2
380 - Commerce, communications & transportation
2
550 - Earth sciences
2
572 - Biochemistry
2
612 - Human physiology
2
615 - Pharmacology & therapeutics
2
616 - Diseases
2
641 - Food & drink
2
005 - Computer programming, programs & data
1
155 - Differential & developmental psychology
1
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