Classification
621 - Applied physics
955
333 - Economics of land & energy
427
600 - Technology
164
620 - Engineering & allied operations
146
330 - Economics
127
363 - Other social problems & services
67
700 - The arts; fine & decorative arts
64
006 - Special computer methods
62
660 - Chemical engineering
55
000 - Computer science, information & general works
50
900 - History & geography
42
304 - Factors affecting social behavior
37
629 - Other branches of engineering
33
380 - Commerce, communications & transportation
32
720 - Architecture
30
541 - Physical chemistry
29
530 - Physics
24
551 - Geology, hydrology & meteorology
24
628 - Sanitary & municipal engineering
24
580 - Plants (Botany)
22
696 - Utilities
21
320 - Political science
19
321 - Systems of governments & states
18
630 - Agriculture & related technologies
16
658 - General management
16
003 - Systems
15
577 - Ecology
14
579 - Microorganisms, fungi & algae
14
610 - Medicine & health
14
500 - Natural sciences & mathematics
13
062 - Organizations in British Isles; in England
12
624 - Civil engineering
12
140 - Specific philosophical schools
11
338 - Production
11
531 - Classical mechanics; solid mechanics
9
547 - Organic chemistry
9
576 - Genetics & evolution
9
340 - Law
8
572 - Biochemistry
8
670 - Manufacturing
8
690 - Buildings
8
910 - Geography & travel
8
662 - Explosives, fuels & related products
7
004 - Data processing & computer science
5
370 - Education
5
697 - Heating, ventilating & air-conditioning
5
539 - Modern physics
4
550 - Earth sciences
4
664 - Food technology
4
331 - Labor economics
3
more ...