Classification
539 - Modern physics
29
530 - Physics
27
523 - Specific celestial bodies & phenomena
13
620 - Engineering & allied operations
10
520 - Astronomy & allied sciences
9
006 - Special computer methods
6
621 - Applied physics
6
004 - Data processing & computer science
5
001 - Knowledge
4
300 - Social sciences
4
500 - Natural sciences & mathematics
3
515 - Analysis
3
670 - Manufacturing
3
005 - Computer programming, programs & data
2
519 - Probabilities & applied mathematics
2
541 - Physical chemistry
2
571 - Physiology & related subjects
2
577 - Ecology
2
610 - Medicine & health
2
629 - Other branches of engineering
2
333 - Economics of land & energy
1
338 - Production
1
414 - Phonology & phonetics
1
510 - Mathematics
1
518 - Numerical analysis
1
531 - Classical mechanics; solid mechanics
1
543 - Analytical chemistry
1
550 - Earth sciences
1
572 - Biochemistry
1
581 - Specific topics in natural history
1
600 - Technology
1
616 - Diseases
1
658 - General management
1
660 - Chemical engineering
1
691 - Building materials
1
700 - The arts; fine & decorative arts
1
900 - History & geography
1