Classification
541 - Physical chemistry
1,200
540 - Chemistry & allied sciences
1,130
547 - Organic chemistry
645
660 - Chemical engineering
523
620 - Engineering & allied operations
416
543 - Analytical chemistry
391
546 - Inorganic chemistry
360
572 - Biochemistry
267
530 - Physics
239
577 - Ecology
231
621 - Applied physics
190
333 - Economics of land & energy
155
363 - Other social problems & services
154
615 - Pharmacology & therapeutics
131
519 - Probabilities & applied mathematics
128
551 - Geology, hydrology & meteorology
97
539 - Modern physics
96
571 - Physiology & related subjects
87
536 - Heat
67
610 - Medicine & health
64
641 - Food & drink
58
664 - Food technology
58
670 - Manufacturing
55
616 - Diseases
54
003 - Systems
53
006 - Special computer methods
51
570 - Life sciences; biology
48
628 - Sanitary & municipal engineering
44
549 - Mineralogy
41
580 - Plants (Botany)
40
531 - Classical mechanics; solid mechanics
39
515 - Analysis
36
630 - Agriculture & related technologies
34
520 - Astronomy & allied sciences
31
629 - Other branches of engineering
29
910 - Geography & travel
29
518 - Numerical analysis
27
548 - Crystallography
27
631 - Techniques, equipment & materials
26
550 - Earth sciences
25
500 - Natural sciences & mathematics
24
542 - Techniques, equipment & materials
23
523 - Specific celestial bodies & phenomena
22
613 - Personal health & safety
22
004 - Data processing & computer science
19
624 - Civil engineering
19
510 - Mathematics
18
634 - Orchards, fruits & forestry
18
677 - Textiles
17
005 - Computer programming, programs & data
14
more ...