Classification
620 - Engineering & allied operations
434
670 - Manufacturing
50
621 - Applied physics
37
531 - Classical mechanics; solid mechanics
20
541 - Physical chemistry
17
530 - Physics
13
660 - Chemical engineering
11
629 - Other branches of engineering
10
628 - Sanitary & municipal engineering
6
624 - Civil engineering
5
610 - Medicine & health
4
690 - Buildings
4
500 - Natural sciences & mathematics
3
537 - Electricity & electronics
3
600 - Technology
3
691 - Building materials
3
363 - Other social problems & services
2
539 - Modern physics
2
546 - Inorganic chemistry
2
617 - Surgery & related medical specialties
2
658 - General management
2
667 - Cleaning, color & coating technologies
2
004 - Data processing & computer science
1
304 - Factors affecting social behavior
1
321 - Systems of governments & states
1
338 - Production
1
502 - Miscellany
1
515 - Analysis
1
519 - Probabilities & applied mathematics
1
520 - Astronomy & allied sciences
1
532 - Fluid mechanics; liquid mechanics
1
533 - Gas mechanics
1
536 - Heat
1
540 - Chemistry & allied sciences
1
543 - Analytical chemistry
1
547 - Organic chemistry
1
550 - Earth sciences
1
577 - Ecology
1
580 - Plants (Botany)
1
607 - Education, research & related topics
1
662 - Explosives, fuels & related products
1
696 - Utilities
1
720 - Architecture
1
900 - History & geography
1