Classification
330 - Economics
320 - Political science
411
630 - Agriculture & related technologies
218
333 - Economics of land & energy
159
363 - Other social problems & services
131
600 - Technology
116
700 - The arts; fine & decorative arts
91
610 - Medicine & health
87
000 - Computer science, information & general works
85
340 - Law
84
300 - Social sciences
75
620 - Engineering & allied operations
62
900 - History & geography
55
380 - Commerce, communications & transportation
49
580 - Plants (Botany)
48
140 - Specific philosophical schools
38
551 - Geology, hydrology & meteorology
38
370 - Education
32
658 - General management
28
576 - Genetics & evolution
27
581 - Specific topics in natural history
27
540 - Chemistry & allied sciences
17
304 - Factors affecting social behavior
15
500 - Natural sciences & mathematics
15
100 - Philosophy & psychology
11
800 - Literature & rhetoric
11
361 - Social problems & social welfare in general
8
200 - Religion
7
400 - Language
7
410 - Linguistics
6
301 - Sociology & anthropology
5
338 - Production
5
657 - Accounting
5
158 - Applied psychology
4
170 - Ethics
4
530 - Physics
4
612 - Human physiology
4
615 - Pharmacology & therapeutics
4
650 - Management & auxiliary services
4
720 - Architecture
4
336 - Public finance
3
297 - Islam, Babism & Bahai Faith
2
360 - Social problems & services; associations
2
381 - Commerce
2
520 - Astronomy & allied sciences
2
780 - Music
2
160 - Logic
1
332 - Financial economics
1
350 - Public administration & military science
1
414 - Phonology & phonetics
1
more ...