Classification
320 - Political science
126
330 - Economics
39
900 - History & geography
28
300 - Social sciences
26
700 - The arts; fine & decorative arts
16
333 - Economics of land & energy
15
380 - Commerce, communications & transportation
14
363 - Other social problems & services
13
100 - Philosophy & psychology
12
140 - Specific philosophical schools
11
600 - Technology
9
301 - Sociology & anthropology
8
327 - International relations
8
410 - Linguistics
7
370 - Education
6
400 - Language
6
000 - Computer science, information & general works
5
200 - Religion
5
551 - Geology, hydrology & meteorology
5
576 - Genetics & evolution
5
581 - Specific topics in natural history
5
780 - Music
5
800 - Literature & rhetoric
5
340 - Law
4
620 - Engineering & allied operations
4
325 - International migration & colonization
3
337 - International economics
3
610 - Medicine & health
3
658 - General management
3
720 - Architecture
3
170 - Ethics
2
303 - Social processes
2
332 - Financial economics
2
384 - Communications; telecommunication
2
630 - Agriculture & related technologies
2
120 - Epistemology, causation & humankind
1
297 - Islam, Babism & Bahai Faith
1
336 - Public finance
1
338 - Production
1
341 - Law of nations
1
345 - Criminal law
1
350 - Public administration & military science
1
355 - Military science
1
361 - Social problems & social welfare in general
1
382 - International commerce
1
500 - Natural sciences & mathematics
1
530 - Physics
1
580 - Plants (Botany)
1
770 - Photography, photographs & computer art
1
947 - Eastern Europe; Russia
1
more ...