Classification
548 - Crystallography
177
530 - Physics
132
540 - Chemistry & allied sciences
69
620 - Engineering & allied operations
69
541 - Physical chemistry
56
539 - Modern physics
38
621 - Applied physics
32
549 - Mineralogy
31
546 - Inorganic chemistry
29
547 - Organic chemistry
22
543 - Analytical chemistry
21
000 - Computer science, information & general works
17
333 - Economics of land & energy
13
571 - Physiology & related subjects
13
700 - The arts; fine & decorative arts
13
610 - Medicine & health
10
600 - Technology
9
572 - Biochemistry
8
536 - Heat
6
512 - Algebra
5
537 - Electricity & electronics
5
576 - Genetics & evolution
5
140 - Specific philosophical schools
4
363 - Other social problems & services
4
551 - Geology, hydrology & meteorology
4
580 - Plants (Botany)
4
660 - Chemical engineering
4
900 - History & geography
4
515 - Analysis
3
531 - Classical mechanics; solid mechanics
3
538 - Magnetism
3
542 - Techniques, equipment & materials
3
615 - Pharmacology & therapeutics
3
500 - Natural sciences & mathematics
2
516 - Geometry
2
570 - Life sciences; biology
2
616 - Diseases
2
004 - Data processing & computer science
1
370 - Education
1
380 - Commerce, communications & transportation
1
400 - Language
1
414 - Phonology & phonetics
1
501 - Philosophy & theory
1
502 - Miscellany
1
510 - Mathematics
1
514 - Topology
1
526 - Mathematical geography
1
535 - Light & infrared & ultraviolet phenomena
1
550 - Earth sciences
1
581 - Specific topics in natural history
1
more ...