Classification
910 - Geography & travel
590
551 - Geology, hydrology & meteorology
154
000 - Computer science, information & general works
114
550 - Earth sciences
101
621 - Applied physics
100
333 - Economics of land & energy
88
363 - Other social problems & services
75
005 - Computer programming, programs & data
58
304 - Factors affecting social behavior
48
004 - Data processing & computer science
45
330 - Economics
44
620 - Engineering & allied operations
41
700 - The arts; fine & decorative arts
41
629 - Other branches of engineering
37
500 - Natural sciences & mathematics
36
006 - Special computer methods
35
624 - Civil engineering
33
600 - Technology
30
900 - History & geography
24
577 - Ecology
23
003 - Systems
19
630 - Agriculture & related technologies
17
380 - Commerce, communications & transportation
16
526 - Mathematical geography
15
320 - Political science
13
658 - General management
12
720 - Architecture
11
140 - Specific philosophical schools
10
631 - Techniques, equipment & materials
10
307 - Communities
9
384 - Communications; telecommunication
9
581 - Specific topics in natural history
9
610 - Medicine & health
9
370 - Education
8
520 - Astronomy & allied sciences
8
580 - Plants (Botany)
8
523 - Specific celestial bodies & phenomena
6
025 - Library operations
5
331 - Labor economics
5
340 - Law
5
519 - Probabilities & applied mathematics
5
530 - Physics
5
628 - Sanitary & municipal engineering
5
634 - Orchards, fruits & forestry
5
400 - Language
4
800 - Literature & rhetoric
4
930 - History of ancient world to ca. 499
4
300 - Social sciences
3
338 - Production
3
414 - Phonology & phonetics
3
more ...