Classification
363 - Other social problems & services
1,252
333 - Economics of land & energy
470
551 - Geology, hydrology & meteorology
374
330 - Economics
308
577 - Ecology
262
628 - Sanitary & municipal engineering
243
700 - The arts; fine & decorative arts
213
620 - Engineering & allied operations
212
600 - Technology
191
610 - Medicine & health
173
000 - Computer science, information & general works
166
660 - Chemical engineering
126
900 - History & geography
113
621 - Applied physics
111
624 - Civil engineering
99
380 - Commerce, communications & transportation
83
572 - Biochemistry
83
630 - Agriculture & related technologies
83
320 - Political science
74
140 - Specific philosophical schools
72
580 - Plants (Botany)
71
540 - Chemistry & allied sciences
66
550 - Earth sciences
53
304 - Factors affecting social behavior
51
910 - Geography & travel
44
658 - General management
40
500 - Natural sciences & mathematics
39
581 - Specific topics in natural history
36
629 - Other branches of engineering
36
340 - Law
35
576 - Genetics & evolution
34
631 - Techniques, equipment & materials
33
615 - Pharmacology & therapeutics
31
344 - Labor, social, education & cultural law
30
541 - Physical chemistry
28
338 - Production
23
579 - Microorganisms, fungi & algae
22
613 - Personal health & safety
21
370 - Education
19
571 - Physiology & related subjects
19
530 - Physics
18
543 - Analytical chemistry
17
720 - Architecture
16
414 - Phonology & phonetics
15
800 - Literature & rhetoric
15
300 - Social sciences
14
690 - Buildings
14
670 - Manufacturing
12
003 - Systems
11
301 - Sociology & anthropology
11
more ...