Classification
363 - Other social problems & services
372
333 - Economics of land & energy
244
610 - Medicine & health
211
577 - Ecology
177
620 - Engineering & allied operations
154
615 - Pharmacology & therapeutics
120
330 - Economics
100
551 - Geology, hydrology & meteorology
100
700 - The arts; fine & decorative arts
87
628 - Sanitary & municipal engineering
85
000 - Computer science, information & general works
84
660 - Chemical engineering
84
580 - Plants (Botany)
74
600 - Technology
74
630 - Agriculture & related technologies
72
540 - Chemistry & allied sciences
64
572 - Biochemistry
63
519 - Probabilities & applied mathematics
62
571 - Physiology & related subjects
60
621 - Applied physics
54
500 - Natural sciences & mathematics
47
579 - Microorganisms, fungi & algae
46
616 - Diseases
42
658 - General management
38
900 - History & geography
38
006 - Special computer methods
36
003 - Systems
32
613 - Personal health & safety
32
140 - Specific philosophical schools
31
631 - Techniques, equipment & materials
31
300 - Social sciences
28
550 - Earth sciences
28
380 - Commerce, communications & transportation
27
570 - Life sciences; biology
25
581 - Specific topics in natural history
24
541 - Physical chemistry
23
576 - Genetics & evolution
22
612 - Human physiology
22
614 - Incidence & prevention of disease
22
320 - Political science
21
304 - Factors affecting social behavior
19
624 - Civil engineering
19
001 - Knowledge
17
338 - Production
17
530 - Physics
16
670 - Manufacturing
16
543 - Analytical chemistry
13
664 - Food technology
12
910 - Geography & travel
12
414 - Phonology & phonetics
11
more ...