Classification
333 - Economics of land & energy
1,566
320 - Political science
1,425
330 - Economics
1,124
363 - Other social problems & services
574
307 - Communities
559
304 - Factors affecting social behavior
520
700 - The arts; fine & decorative arts
395
900 - History & geography
287
600 - Technology
275
000 - Computer science, information & general works
269
610 - Medicine & health
266
710 - Civic & landscape art
246
551 - Geology, hydrology & meteorology
232
380 - Commerce, communications & transportation
228
720 - Architecture
210
300 - Social sciences
199
620 - Engineering & allied operations
170
140 - Specific philosophical schools
157
370 - Education
141
338 - Production
139
577 - Ecology
131
910 - Geography & travel
125
630 - Agriculture & related technologies
121
658 - General management
80
580 - Plants (Botany)
78
306 - Culture & institutions
67
581 - Specific topics in natural history
62
301 - Sociology & anthropology
61
340 - Law
60
624 - Civil engineering
48
576 - Genetics & evolution
47
800 - Literature & rhetoric
41
305 - Social groups
38
500 - Natural sciences & mathematics
35
628 - Sanitary & municipal engineering
33
621 - Applied physics
32
629 - Other branches of engineering
32
361 - Social problems & social welfare in general
30
100 - Philosophy & psychology
28
388 - Transportation; ground transportation
27
414 - Phonology & phonetics
27
690 - Buildings
25
200 - Religion
23
336 - Public finance
23
550 - Earth sciences
23
530 - Physics
19
170 - Ethics
17
400 - Language
17
711 - Area planning
17
540 - Chemistry & allied sciences
15
more ...