Classification
330 - Economics
333 - Economics of land & energy
320 - Political science
631
363 - Other social problems & services
485
600 - Technology
424
700 - The arts; fine & decorative arts
346
000 - Computer science, information & general works
273
620 - Engineering & allied operations
228
610 - Medicine & health
223
900 - History & geography
217
380 - Commerce, communications & transportation
216
140 - Specific philosophical schools
132
551 - Geology, hydrology & meteorology
127
370 - Education
124
304 - Factors affecting social behavior
119
630 - Agriculture & related technologies
108
580 - Plants (Botany)
94
658 - General management
74
581 - Specific topics in natural history
70
340 - Law
68
576 - Genetics & evolution
56
500 - Natural sciences & mathematics
51
100 - Philosophy & psychology
44
300 - Social sciences
39
336 - Public finance
39
720 - Architecture
36
170 - Ethics
29
800 - Literature & rhetoric
29
540 - Chemistry & allied sciences
28
530 - Physics
26
361 - Social problems & social welfare in general
22
400 - Language
21
657 - Accounting
16
301 - Sociology & anthropology
14
200 - Religion
13
350 - Public administration & military science
13
414 - Phonology & phonetics
11
297 - Islam, Babism & Bahai Faith
10
410 - Linguistics
10
791 - Public performances
8
612 - Human physiology
7
332 - Financial economics
6
650 - Management & auxiliary services
5
520 - Astronomy & allied sciences
4
780 - Music
4
158 - Applied psychology
3
331 - Labor economics
3
360 - Social problems & services; associations
3
381 - Commerce
3
550 - Earth sciences
3
more ...