Classification
620 - Engineering & allied operations
922
621 - Applied physics
331
531 - Classical mechanics; solid mechanics
162
530 - Physics
159
515 - Analysis
124
629 - Other branches of engineering
121
003 - Systems
45
518 - Numerical analysis
45
519 - Probabilities & applied mathematics
42
660 - Chemical engineering
39
333 - Economics of land & energy
35
600 - Technology
35
551 - Geology, hydrology & meteorology
34
532 - Fluid mechanics; liquid mechanics
32
624 - Civil engineering
28
536 - Heat
26
610 - Medicine & health
22
000 - Computer science, information & general works
21
571 - Physiology & related subjects
21
700 - The arts; fine & decorative arts
21
670 - Manufacturing
20
900 - History & geography
18
500 - Natural sciences & mathematics
17
510 - Mathematics
14
550 - Earth sciences
12
363 - Other social problems & services
10
534 - Sound & related vibrations
10
006 - Special computer methods
9
380 - Commerce, communications & transportation
9
512 - Algebra
9
541 - Physical chemistry
8
612 - Human physiology
8
616 - Diseases
8
627 - Hydraulic engineering
8
300 - Social sciences
7
001 - Knowledge
6
570 - Life sciences; biology
6
628 - Sanitary & municipal engineering
6
523 - Specific celestial bodies & phenomena
5
533 - Gas mechanics
5
539 - Modern physics
5
004 - Data processing & computer science
4
140 - Specific philosophical schools
4
516 - Geometry
4
526 - Mathematical geography
4
576 - Genetics & evolution
4
664 - Food technology
4
667 - Cleaning, color & coating technologies
4
690 - Buildings
4
340 - Law
3
more ...