Classification
900 - History & geography
30
700 - The arts; fine & decorative arts
27
320 - Political science
19
370 - Education
14
333 - Economics of land & energy
13
325 - International migration & colonization
11
000 - Computer science, information & general works
9
100 - Philosophy & psychology
9
140 - Specific philosophical schools
9
363 - Other social problems & services
9
330 - Economics
8
120 - Epistemology, causation & humankind
7
327 - International relations
7
380 - Commerce, communications & transportation
6
780 - Music
6
200 - Religion
5
300 - Social sciences
5
301 - Sociology & anthropology
5
610 - Medicine & health
5
340 - Law
4
551 - Geology, hydrology & meteorology
4
800 - Literature & rhetoric
4
304 - Factors affecting social behavior
3
305 - Social groups
3
400 - Language
3
580 - Plants (Botany)
3
581 - Specific topics in natural history
3
600 - Technology
3
809 - History, description & criticism
3
170 - Ethics
2
297 - Islam, Babism & Bahai Faith
2
341 - Law of nations
2
500 - Natural sciences & mathematics
2
720 - Architecture
2
909 - World history
2
968 - Southern Africa; Republic of South Africa
2
069 - Museum science
1
128 - Humankind
1
306 - Culture & institutions
1
321 - Systems of governments & states
1
323 - Civil & political rights
1
338 - Production
1
343 - Military, tax, trade & industrial law
1
355 - Military science
1
364 - Criminology
1
378 - Higher education
1
526 - Mathematical geography
1
576 - Genetics & evolution
1
590 - Animals (Zoology)
1
630 - Agriculture & related technologies
1
more ...