Classification
551 - Geology, hydrology & meteorology
1,251
624 - Civil engineering
499
550 - Earth sciences
236
363 - Other social problems & services
143
333 - Economics of land & energy
133
620 - Engineering & allied operations
100
910 - Geography & travel
98
577 - Ecology
87
549 - Mineralogy
85
621 - Applied physics
80
700 - The arts; fine & decorative arts
64
414 - Phonology & phonetics
58
900 - History & geography
46
553 - Economic geology
44
600 - Technology
38
526 - Mathematical geography
37
690 - Buildings
35
628 - Sanitary & municipal engineering
34
560 - Paleontology; paleozoology
33
000 - Computer science, information & general works
31
330 - Economics
27
531 - Classical mechanics; solid mechanics
21
630 - Agriculture & related technologies
21
006 - Special computer methods
20
320 - Political science
18
519 - Probabilities & applied mathematics
18
576 - Genetics & evolution
17
500 - Natural sciences & mathematics
16
530 - Physics
15
631 - Techniques, equipment & materials
15
380 - Commerce, communications & transportation
14
691 - Building materials
14
304 - Factors affecting social behavior
13
540 - Chemistry & allied sciences
13
541 - Physical chemistry
13
571 - Physiology & related subjects
13
930 - History of ancient world to ca. 499
12
520 - Astronomy & allied sciences
11
523 - Specific celestial bodies & phenomena
11
627 - Hydraulic engineering
11
003 - Systems
10
140 - Specific philosophical schools
9
370 - Education
9
581 - Specific topics in natural history
9
610 - Medicine & health
9
660 - Chemical engineering
8
301 - Sociology & anthropology
7
340 - Law
7
378 - Higher education
7
579 - Microorganisms, fungi & algae
7
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