Classification
330 - Economics
20
519 - Probabilities & applied mathematics
18
620 - Engineering & allied operations
11
306 - Culture & institutions
10
621 - Applied physics
9
006 - Special computer methods
6
300 - Social sciences
6
320 - Political science
6
333 - Economics of land & energy
6
338 - Production
6
370 - Education
6
658 - General management
6
530 - Physics
5
004 - Data processing & computer science
4
005 - Computer programming, programs & data
4
378 - Higher education
4
500 - Natural sciences & mathematics
4
515 - Analysis
4
541 - Physical chemistry
4
600 - Technology
4
302 - Social interaction
3
336 - Public finance
3
510 - Mathematics
3
516 - Geometry
3
531 - Classical mechanics; solid mechanics
3
551 - Geology, hydrology & meteorology
3
670 - Manufacturing
3
900 - History & geography
3
001 - Knowledge
2
100 - Philosophy & psychology
2
128 - Humankind
2
153 - Mental processes & intelligence
2
331 - Labor economics
2
332 - Financial economics
2
511 - General principles of mathematics
2
512 - Algebra
2
514 - Topology
2
520 - Astronomy & allied sciences
2
539 - Modern physics
2
570 - Life sciences; biology
2
580 - Plants (Botany)
2
610 - Medicine & health
2
630 - Agriculture & related technologies
2
700 - The arts; fine & decorative arts
2
000 - Computer science, information & general works
1
003 - Systems
1
120 - Epistemology, causation & humankind
1
155 - Differential & developmental psychology
1
160 - Logic
1
301 - Sociology & anthropology
1
more ...