Classification
005 - Computer programming, programs & data
33
006 - Special computer methods
28
306 - Culture & institutions
28
304 - Factors affecting social behavior
27
333 - Economics of land & energy
19
327 - International relations
16
658 - General management
14
320 - Political science
13
577 - Ecology
12
551 - Geology, hydrology & meteorology
11
338 - Production
10
340 - Law
9
610 - Medicine & health
9
363 - Other social problems & services
8
004 - Data processing & computer science
7
621 - Applied physics
7
630 - Agriculture & related technologies
7
155 - Differential & developmental psychology
6
305 - Social groups
6
910 - Geography & travel
6
930 - History of ancient world to ca. 499
6
150 - Psychology
5
301 - Sociology & anthropology
5
300 - Social sciences
4
341 - Law of nations
4
370 - Education
4
550 - Earth sciences
4
613 - Personal health & safety
4
003 - Systems
3
303 - Social processes
3
330 - Economics
3
343 - Military, tax, trade & industrial law
3
345 - Criminal law
3
364 - Criminology
3
371 - Schools & their activities; special education
3
375 - Curricula
3
507 - Education, research & related topics
3
570 - Life sciences; biology
3
576 - Genetics & evolution
3
631 - Techniques, equipment & materials
3
670 - Manufacturing
3
040 - [Unassigned]
2
299 - Religions not provided for elsewhere
2
307 - Communities
2
368 - Insurance
2
379 - Public policy issues in education
2
418 - Standard usage & applied linguistics
2
515 - Analysis
2
523 - Specific celestial bodies & phenomena
2
578 - Natural history of organisms
2
more ...