Classification
333 - Economics of land & energy
239
330 - Economics
150
363 - Other social problems & services
72
621 - Applied physics
46
338 - Production
44
320 - Political science
37
304 - Factors affecting social behavior
24
551 - Geology, hydrology & meteorology
24
620 - Engineering & allied operations
23
700 - The arts; fine & decorative arts
23
600 - Technology
22
610 - Medicine & health
21
630 - Agriculture & related technologies
18
658 - General management
18
660 - Chemical engineering
18
900 - History & geography
18
000 - Computer science, information & general works
17
140 - Specific philosophical schools
14
300 - Social sciences
13
577 - Ecology
13
581 - Specific topics in natural history
13
340 - Law
12
380 - Commerce, communications & transportation
12
628 - Sanitary & municipal engineering
12
370 - Education
7
332 - Financial economics
6
500 - Natural sciences & mathematics
6
670 - Manufacturing
6
344 - Labor, social, education & cultural law
5
570 - Life sciences; biology
5
576 - Genetics & evolution
5
634 - Orchards, fruits & forestry
5
301 - Sociology & anthropology
4
346 - Private law
4
550 - Earth sciences
4
580 - Plants (Botany)
4
624 - Civil engineering
4
170 - Ethics
3
303 - Social processes
3
341 - Law of nations
3
519 - Probabilities & applied mathematics
3
530 - Physics
3
540 - Chemistry & allied sciences
3
553 - Economic geology
3
627 - Hydraulic engineering
3
631 - Techniques, equipment & materials
3
800 - Literature & rhetoric
3
100 - Philosophy & psychology
2
200 - Religion
2
307 - Communities
2
more ...