Classification
550 - Earth sciences
970
551 - Geology, hydrology & meteorology
711
624 - Civil engineering
677
910 - Geography & travel
472
700 - The arts; fine & decorative arts
446
363 - Other social problems & services
427
519 - Probabilities & applied mathematics
396
333 - Economics of land & energy
283
620 - Engineering & allied operations
216
621 - Applied physics
200
577 - Ecology
167
500 - Natural sciences & mathematics
131
000 - Computer science, information & general works
121
600 - Technology
121
530 - Physics
120
900 - History & geography
109
330 - Economics
86
320 - Political science
76
300 - Social sciences
71
630 - Agriculture & related technologies
67
006 - Special computer methods
58
520 - Astronomy & allied sciences
57
526 - Mathematical geography
57
304 - Factors affecting social behavior
54
540 - Chemistry & allied sciences
47
631 - Techniques, equipment & materials
47
140 - Specific philosophical schools
43
005 - Computer programming, programs & data
41
610 - Medicine & health
41
581 - Specific topics in natural history
40
003 - Systems
39
580 - Plants (Botany)
39
570 - Life sciences; biology
36
576 - Genetics & evolution
36
628 - Sanitary & municipal engineering
36
523 - Specific celestial bodies & phenomena
32
549 - Mineralogy
32
720 - Architecture
32
301 - Sociology & anthropology
29
004 - Data processing & computer science
28
380 - Commerce, communications & transportation
27
531 - Classical mechanics; solid mechanics
27
629 - Other branches of engineering
27
100 - Philosophy & psychology
25
515 - Analysis
25
690 - Buildings
25
340 - Law
22
560 - Paleontology; paleozoology
22
658 - General management
22
414 - Phonology & phonetics
21
more ...