Classification
537 - Electricity & electronics
341
621 - Applied physics
190
535 - Light & infrared & ultraviolet phenomena
144
530 - Physics
109
620 - Engineering & allied operations
49
539 - Modern physics
35
531 - Classical mechanics; solid mechanics
14
500 - Natural sciences & mathematics
12
700 - The arts; fine & decorative arts
12
538 - Magnetism
11
515 - Analysis
10
520 - Astronomy & allied sciences
10
333 - Economics of land & energy
9
543 - Analytical chemistry
9
000 - Computer science, information & general works
8
534 - Sound & related vibrations
7
541 - Physical chemistry
7
600 - Technology
6
523 - Specific celestial bodies & phenomena
5
551 - Geology, hydrology & meteorology
5
516 - Geometry
4
519 - Probabilities & applied mathematics
4
536 - Heat
4
550 - Earth sciences
4
571 - Physiology & related subjects
4
900 - History & geography
4
380 - Commerce, communications & transportation
3
670 - Manufacturing
3
510 - Mathematics
2
518 - Numerical analysis
2
540 - Chemistry & allied sciences
2
576 - Genetics & evolution
2
617 - Surgery & related medical specialties
2
629 - Other branches of engineering
2
003 - Systems
1
004 - Data processing & computer science
1
006 - Special computer methods
1
330 - Economics
1
363 - Other social problems & services
1
400 - Language
1
501 - Philosophy & theory
1
509 - Historical, geographic & persons treatment
1
512 - Algebra
1
526 - Mathematical geography
1
548 - Crystallography
1
549 - Mineralogy
1
610 - Medicine & health
1
616 - Diseases
1
630 - Agriculture & related technologies
1
770 - Photography, photographs & computer art
1
more ...