Classification
577 - Ecology
115
515 - Analysis
62
570 - Life sciences; biology
59
519 - Probabilities & applied mathematics
45
304 - Factors affecting social behavior
42
576 - Genetics & evolution
30
530 - Physics
27
333 - Economics of land & energy
25
330 - Economics
24
610 - Medicine & health
23
003 - Systems
19
580 - Plants (Botany)
19
590 - Animals (Zoology)
17
581 - Specific topics in natural history
16
006 - Special computer methods
15
363 - Other social problems & services
14
500 - Natural sciences & mathematics
14
510 - Mathematics
14
616 - Diseases
14
571 - Physiology & related subjects
13
000 - Computer science, information & general works
11
004 - Data processing & computer science
11
551 - Geology, hydrology & meteorology
11
630 - Agriculture & related technologies
10
579 - Microorganisms, fungi & algae
9
620 - Engineering & allied operations
9
700 - The arts; fine & decorative arts
9
300 - Social sciences
8
591 - Specific topics in natural history
7
592 - Invertebrates
7
614 - Incidence & prevention of disease
7
600 - Technology
5
611 - Human anatomy, cytology & histology
5
612 - Human physiology
5
621 - Applied physics
5
900 - History & geography
5
910 - Geography & travel
5
338 - Production
4
599 - Mammals
4
634 - Orchards, fruits & forestry
4
660 - Chemical engineering
4
001 - Knowledge
3
005 - Computer programming, programs & data
3
301 - Sociology & anthropology
3
305 - Social groups
3
320 - Political science
3
370 - Education
3
597 - Cold-blooded vertebrates; fishes
3
613 - Personal health & safety
3
636 - Animal husbandry
3
more ...