Classification
001 - Knowledge
1
003 - Systems
15
004 - Data processing & computer science
10
005 - Computer programming, programs & data
2
006 - Special computer methods
18
100 - Philosophy & psychology
1
113 - Cosmology
1
153 - Mental processes & intelligence
1
158 - Applied psychology
1
170 - Ethics
2
174 - Occupational ethics
2
300 - Social sciences
1
301 - Sociology & anthropology
3
303 - Social processes
4
304 - Factors affecting social behavior
84
305 - Social groups
2
306 - Culture & institutions
1
307 - Communities
2
320 - Political science
21
321 - Systems of governments & states
27
327 - International relations
6
330 - Economics
16
332 - Financial economics
7
333 - Economics of land & energy
702
337 - International economics
5
338 - Production
276
339 - Macroeconomics & related topics
4
340 - Law
10
341 - Law of nations
4
342 - Constitutional & administrative law
1
343 - Military, tax, trade & industrial law
9
344 - Labor, social, education & cultural law
7
350 - Public administration & military science
1
351 - Public administration
1
352 - General considerations of public administration
3
361 - Social problems & social welfare in general
1
363 - Other social problems & services
45
370 - Education
1
500 - Natural sciences & mathematics
1
507 - Education, research & related topics
1
511 - General principles of mathematics
1
519 - Probabilities & applied mathematics
5
520 - Astronomy & allied sciences
1
530 - Physics
13
536 - Heat
5
539 - Modern physics
2
541 - Physical chemistry
5
546 - Inorganic chemistry
1
547 - Organic chemistry
3
548 - Crystallography
1
more ...