Classification
320 - Political science
173
327 - International relations
166
900 - History & geography
139
330 - Economics
52
333 - Economics of land & energy
34
355 - Military science
33
700 - The arts; fine & decorative arts
30
300 - Social sciences
26
909 - World history
26
363 - Other social problems & services
24
338 - Production
23
306 - Culture & institutions
21
940 - History of Europe
21
304 - Factors affecting social behavior
17
341 - Law of nations
17
791 - Public performances
16
509 - Historical, geographic & persons treatment
15
301 - Sociology & anthropology
14
500 - Natural sciences & mathematics
14
800 - Literature & rhetoric
13
000 - Computer science, information & general works
12
303 - Social processes
12
305 - Social groups
12
973 - United States
12
551 - Geology, hydrology & meteorology
11
620 - Engineering & allied operations
11
629 - Other branches of engineering
11
340 - Law
10
658 - General management
10
140 - Specific philosophical schools
9
530 - Physics
9
600 - Technology
9
004 - Data processing & computer science
8
302 - Social interaction
8
380 - Commerce, communications & transportation
8
621 - Applied physics
8
337 - International economics
7
780 - Music
7
809 - History, description & criticism
7
943 - Central Europe; Germany
7
200 - Religion
6
297 - Islam, Babism & Bahai Faith
6
322 - Relation of state to organized groups
6
370 - Education
6
610 - Medicine & health
6
342 - Constitutional & administrative law
5
907 - Education, research & related topics
5
947 - Eastern Europe; Russia
5
959 - Southeast Asia
5
331 - Labor economics
4
more ...