Classification
530 - Physics
1,234
539 - Modern physics
122
541 - Physical chemistry
120
620 - Engineering & allied operations
84
515 - Analysis
60
501 - Philosophy & theory
58
621 - Applied physics
51
500 - Natural sciences & mathematics
47
333 - Economics of land & energy
40
512 - Algebra
37
519 - Probabilities & applied mathematics
36
700 - The arts; fine & decorative arts
35
006 - Special computer methods
28
004 - Data processing & computer science
26
535 - Light & infrared & ultraviolet phenomena
22
510 - Mathematics
19
005 - Computer programming, programs & data
16
000 - Computer science, information & general works
15
003 - Systems
15
516 - Geometry
15
520 - Astronomy & allied sciences
15
536 - Heat
15
523 - Specific celestial bodies & phenomena
14
514 - Topology
13
540 - Chemistry & allied sciences
13
546 - Inorganic chemistry
13
531 - Classical mechanics; solid mechanics
12
537 - Electricity & electronics
12
547 - Organic chemistry
12
518 - Numerical analysis
9
040 - [Unassigned]
8
542 - Techniques, equipment & materials
8
300 - Social sciences
7
538 - Magnetism
7
571 - Physiology & related subjects
7
600 - Technology
7
153 - Mental processes & intelligence
6
511 - General principles of mathematics
6
572 - Biochemistry
6
658 - General management
6
100 - Philosophy & psychology
5
330 - Economics
5
331 - Labor economics
5
509 - Historical, geographic & persons treatment
5
543 - Analytical chemistry
5
001 - Knowledge
4
063 - Organizations in central Europe; in Germany
4
120 - Epistemology, causation & humankind
4
629 - Other branches of engineering
4
900 - History & geography
4
more ...