Classification
620 - Engineering & allied operations
384
691 - Building materials
210
690 - Buildings
138
624 - Civil engineering
68
330 - Economics
49
720 - Architecture
47
320 - Political science
39
600 - Technology
36
900 - History & geography
36
333 - Economics of land & energy
35
700 - The arts; fine & decorative arts
29
621 - Applied physics
27
670 - Manufacturing
23
006 - Special computer methods
20
530 - Physics
19
304 - Factors affecting social behavior
18
363 - Other social problems & services
17
696 - Utilities
17
628 - Sanitary & municipal engineering
15
629 - Other branches of engineering
15
693 - Specific materials & purposes
14
531 - Classical mechanics; solid mechanics
10
000 - Computer science, information & general works
8
610 - Medicine & health
8
627 - Hydraulic engineering
7
500 - Natural sciences & mathematics
6
538 - Magnetism
6
540 - Chemistry & allied sciences
6
541 - Physical chemistry
6
551 - Geology, hydrology & meteorology
6
660 - Chemical engineering
6
630 - Agriculture & related technologies
5
536 - Heat
4
547 - Organic chemistry
4
658 - General management
4
800 - Literature & rhetoric
4
062 - Organizations in British Isles; in England
3
380 - Commerce, communications & transportation
3
414 - Phonology & phonetics
3
515 - Analysis
3
580 - Plants (Botany)
3
005 - Computer programming, programs & data
2
160 - Logic
2
300 - Social sciences
2
301 - Sociology & anthropology
2
340 - Law
2
539 - Modern physics
2
546 - Inorganic chemistry
2
548 - Crystallography
2
576 - Genetics & evolution
2
more ...