Classification
300 - Social sciences
658 - General management
441
302 - Social interaction
407
330 - Economics
324
338 - Production
219
500 - Natural sciences & mathematics
115
670 - Manufacturing
114
650 - Management & auxiliary services
78
153 - Mental processes & intelligence
55
331 - Labor economics
55
158 - Applied psychology
46
384 - Communications; telecommunication
36
000 - Computer science, information & general works
28
600 - Technology
22
620 - Engineering & allied operations
21
320 - Political science
19
380 - Commerce, communications & transportation
18
381 - Commerce
18
370 - Education
13
700 - The arts; fine & decorative arts
13
610 - Medicine & health
9
745 - Decorative arts
9
100 - Philosophy & psychology
8
333 - Economics of land & energy
8
900 - History & geography
8
150 - Psychology
7
362 - Social welfare problems & services
7
001 - Knowledge
6
004 - Data processing & computer science
6
301 - Sociology & anthropology
6
140 - Specific philosophical schools
5
303 - Social processes
5
363 - Other social problems & services
5
170 - Ethics
4
332 - Financial economics
4
630 - Agriculture & related technologies
4
006 - Special computer methods
3
160 - Logic
3
371 - Schools & their activities; special education
3
400 - Language
3
551 - Geology, hydrology & meteorology
3
005 - Computer programming, programs & data
2
025 - Library operations
2
120 - Epistemology, causation & humankind
2
155 - Differential & developmental psychology
2
304 - Factors affecting social behavior
2
510 - Mathematics
2
530 - Physics
2
581 - Specific topics in natural history
2
720 - Architecture
2
more ...