Classification
530 - Physics
8,121
610 - Medicine & health
4,514
620 - Engineering & allied operations
4,465
621 - Applied physics
3,868
616 - Diseases
3,809
500 - Natural sciences & mathematics
2,033
541 - Physical chemistry
1,842
515 - Analysis
1,627
600 - Technology
1,612
330 - Economics
1,568
333 - Economics of land & energy
1,501
539 - Modern physics
1,491
005 - Computer programming, programs & data
1,471
006 - Special computer methods
1,359
004 - Data processing & computer science
1,334
551 - Geology, hydrology & meteorology
1,272
519 - Probabilities & applied mathematics
1,266
520 - Astronomy & allied sciences
1,250
540 - Chemistry & allied sciences
1,120
700 - The arts; fine & decorative arts
1,053
000 - Computer science, information & general works
905
617 - Surgery & related medical specialties
871
571 - Physiology & related subjects
761
523 - Specific celestial bodies & phenomena
747
550 - Earth sciences
743
363 - Other social problems & services
728
658 - General management
726
629 - Other branches of engineering
703
900 - History & geography
641
300 - Social sciences
639
910 - Geography & travel
630
510 - Mathematics
626
531 - Classical mechanics; solid mechanics
563
820 - English & Old English literatures
540
003 - Systems
531
612 - Human physiology
500
577 - Ecology
491
370 - Education
435
331 - Labor economics
425
615 - Pharmacology & therapeutics
421
572 - Biochemistry
420
512 - Algebra
405
501 - Philosophy & theory
399
660 - Chemical engineering
388
570 - Life sciences; biology
376
543 - Analytical chemistry
367
320 - Political science
358
547 - Organic chemistry
355
537 - Electricity & electronics
354
304 - Factors affecting social behavior
349
more ...