Classification
543 - Analytical chemistry
377
541 - Physical chemistry
120
620 - Engineering & allied operations
111
540 - Chemistry & allied sciences
78
577 - Ecology
76
572 - Biochemistry
65
660 - Chemical engineering
55
547 - Organic chemistry
43
000 - Computer science, information & general works
29
363 - Other social problems & services
29
621 - Applied physics
29
664 - Food technology
28
641 - Food & drink
27
615 - Pharmacology & therapeutics
26
571 - Physiology & related subjects
25
610 - Medicine & health
21
551 - Geology, hydrology & meteorology
19
546 - Inorganic chemistry
16
333 - Economics of land & energy
15
700 - The arts; fine & decorative arts
13
570 - Life sciences; biology
11
616 - Diseases
10
530 - Physics
9
580 - Plants (Botany)
9
140 - Specific philosophical schools
8
600 - Technology
7
502 - Miscellany
6
006 - Special computer methods
5
628 - Sanitary & municipal engineering
5
670 - Manufacturing
5
900 - History & geography
5
500 - Natural sciences & mathematics
4
539 - Modern physics
4
330 - Economics
3
612 - Human physiology
3
630 - Agriculture & related technologies
3
631 - Techniques, equipment & materials
3
003 - Systems
2
519 - Probabilities & applied mathematics
2
537 - Electricity & electronics
2
549 - Mineralogy
2
613 - Personal health & safety
2
614 - Incidence & prevention of disease
2
634 - Orchards, fruits & forestry
2
910 - Geography & travel
2
004 - Data processing & computer science
1
120 - Epistemology, causation & humankind
1
301 - Sociology & anthropology
1
370 - Education
1
380 - Commerce, communications & transportation
1
more ...