Classification
620 - Engineering & allied operations
40
658 - General management
36
300 - Social sciences
26
330 - Economics
24
621 - Applied physics
21
530 - Physics
17
629 - Other branches of engineering
15
616 - Diseases
14
500 - Natural sciences & mathematics
13
610 - Medicine & health
13
338 - Production
12
670 - Manufacturing
12
650 - Management & auxiliary services
11
510 - Mathematics
10
302 - Social interaction
9
331 - Labor economics
9
003 - Systems
8
158 - Applied psychology
7
340 - Law
7
516 - Geometry
6
519 - Probabilities & applied mathematics
6
550 - Earth sciences
6
617 - Surgery & related medical specialties
6
150 - Psychology
5
531 - Classical mechanics; solid mechanics
5
580 - Plants (Botany)
5
900 - History & geography
5
306 - Culture & institutions
4
333 - Economics of land & energy
4
370 - Education
4
380 - Commerce, communications & transportation
4
384 - Communications; telecommunication
4
551 - Geology, hydrology & meteorology
4
570 - Life sciences; biology
4
004 - Data processing & computer science
3
155 - Differential & developmental psychology
3
160 - Logic
3
304 - Factors affecting social behavior
3
371 - Schools & their activities; special education
3
590 - Animals (Zoology)
3
660 - Chemical engineering
3
000 - Computer science, information & general works
2
006 - Special computer methods
2
109 - Historical & collected persons treatment
2
120 - Epistemology, causation & humankind
2
153 - Mental processes & intelligence
2
200 - Religion
2
305 - Social groups
2
320 - Political science
2
342 - Constitutional & administrative law
2
more ...