Classification
551 - Geology, hydrology & meteorology
563
550 - Earth sciences
91
577 - Ecology
87
910 - Geography & travel
57
500 - Natural sciences & mathematics
47
333 - Economics of land & energy
34
363 - Other social problems & services
28
620 - Engineering & allied operations
25
621 - Applied physics
24
534 - Sound & related vibrations
15
627 - Hydraulic engineering
15
526 - Mathematical geography
13
531 - Classical mechanics; solid mechanics
13
578 - Natural history of organisms
12
600 - Technology
11
700 - The arts; fine & decorative arts
11
624 - Civil engineering
8
304 - Factors affecting social behavior
7
549 - Mineralogy
7
581 - Specific topics in natural history
7
900 - History & geography
6
000 - Computer science, information & general works
5
003 - Systems
5
380 - Commerce, communications & transportation
5
560 - Paleontology; paleozoology
5
006 - Special computer methods
4
140 - Specific philosophical schools
4
320 - Political science
4
341 - Law of nations
4
530 - Physics
4
590 - Animals (Zoology)
4
330 - Economics
3
344 - Labor, social, education & cultural law
3
540 - Chemistry & allied sciences
3
571 - Physiology & related subjects
3
628 - Sanitary & municipal engineering
3
629 - Other branches of engineering
3
519 - Probabilities & applied mathematics
2
535 - Light & infrared & ultraviolet phenomena
2
543 - Analytical chemistry
2
553 - Economic geology
2
570 - Life sciences; biology
2
572 - Biochemistry
2
574 - [Unassigned]
2
579 - Microorganisms, fungi & algae
2
930 - History of ancient world to ca. 499
2
057 - Serials in Slavic languages
1
155 - Differential & developmental psychology
1
306 - Culture & institutions
1
338 - Production
1
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