Classification
620 - Engineering & allied operations
1,106
621 - Applied physics
179
530 - Physics
120
531 - Classical mechanics; solid mechanics
111
670 - Manufacturing
103
600 - Technology
100
541 - Physical chemistry
95
900 - History & geography
77
700 - The arts; fine & decorative arts
67
500 - Natural sciences & mathematics
58
540 - Chemistry & allied sciences
53
660 - Chemical engineering
50
333 - Economics of land & energy
39
610 - Medicine & health
29
546 - Inorganic chemistry
25
363 - Other social problems & services
24
539 - Modern physics
21
543 - Analytical chemistry
20
624 - Civil engineering
17
691 - Building materials
17
667 - Cleaning, color & coating technologies
15
547 - Organic chemistry
14
548 - Crystallography
13
330 - Economics
12
580 - Plants (Botany)
12
629 - Other branches of engineering
12
519 - Probabilities & applied mathematics
11
538 - Magnetism
10
549 - Mineralogy
10
630 - Agriculture & related technologies
10
571 - Physiology & related subjects
9
576 - Genetics & evolution
9
380 - Commerce, communications & transportation
8
537 - Electricity & electronics
8
570 - Life sciences; biology
8
690 - Buildings
8
000 - Computer science, information & general works
7
006 - Special computer methods
6
414 - Phonology & phonetics
6
628 - Sanitary & municipal engineering
6
664 - Food technology
6
668 - Technology of other organic products
6
003 - Systems
5
550 - Earth sciences
5
572 - Biochemistry
5
641 - Food & drink
5
720 - Architecture
5
800 - Literature & rhetoric
5
510 - Mathematics
4
534 - Sound & related vibrations
4
more ...