Classification
660 - Chemical engineering
743
620 - Engineering & allied operations
271
621 - Applied physics
241
541 - Physical chemistry
162
547 - Organic chemistry
98
670 - Manufacturing
90
629 - Other branches of engineering
78
003 - Systems
66
363 - Other social problems & services
56
540 - Chemistry & allied sciences
47
543 - Analytical chemistry
44
546 - Inorganic chemistry
42
536 - Heat
30
530 - Physics
27
641 - Food & drink
25
664 - Food technology
25
600 - Technology
23
333 - Economics of land & energy
22
572 - Biochemistry
19
531 - Classical mechanics; solid mechanics
18
624 - Civil engineering
16
628 - Sanitary & municipal engineering
15
577 - Ecology
12
658 - General management
11
615 - Pharmacology & therapeutics
10
610 - Medicine & health
9
662 - Explosives, fuels & related products
9
677 - Textiles
8
519 - Probabilities & applied mathematics
7
667 - Cleaning, color & coating technologies
7
330 - Economics
6
549 - Mineralogy
6
551 - Geology, hydrology & meteorology
6
579 - Microorganisms, fungi & algae
6
690 - Buildings
6
700 - The arts; fine & decorative arts
6
515 - Analysis
5
518 - Numerical analysis
5
539 - Modern physics
5
571 - Physiology & related subjects
5
616 - Diseases
5
632 - Plant injuries, diseases & pests
5
000 - Computer science, information & general works
4
006 - Special computer methods
4
304 - Factors affecting social behavior
4
900 - History & geography
4
005 - Computer programming, programs & data
3
338 - Production
3
380 - Commerce, communications & transportation
3
570 - Life sciences; biology
3
more ...