Classification
551 - Geology, hydrology & meteorology
17
621 - Applied physics
16
576 - Genetics & evolution
11
577 - Ecology
8
363 - Other social problems & services
7
560 - Paleontology; paleozoology
7
333 - Economics of land & energy
6
590 - Animals (Zoology)
6
001 - Knowledge
5
300 - Social sciences
5
620 - Engineering & allied operations
5
541 - Physical chemistry
4
550 - Earth sciences
4
580 - Plants (Botany)
4
301 - Sociology & anthropology
3
536 - Heat
3
571 - Physiology & related subjects
3
660 - Chemical engineering
3
006 - Special computer methods
2
572 - Biochemistry
2
628 - Sanitary & municipal engineering
2
005 - Computer programming, programs & data
1
338 - Production
1
526 - Mathematical geography
1
531 - Classical mechanics; solid mechanics
1
540 - Chemistry & allied sciences
1
570 - Life sciences; biology
1
579 - Microorganisms, fungi & algae
1
616 - Diseases
1
630 - Agriculture & related technologies
1
670 - Manufacturing
1
910 - Geography & travel
1
930 - History of ancient world to ca. 499
1