Classification
900 - History & geography
73
320 - Political science
34
330 - Economics
22
940 - History of Europe
18
700 - The arts; fine & decorative arts
13
338 - Production
10
340 - Law
9
300 - Social sciences
8
301 - Sociology & anthropology
8
332 - Financial economics
8
355 - Military science
8
510 - Mathematics
8
800 - Literature & rhetoric
8
370 - Education
7
616 - Diseases
7
610 - Medicine & health
6
620 - Engineering & allied operations
6
000 - Computer science, information & general works
5
305 - Social groups
5
306 - Culture & institutions
5
327 - International relations
5
342 - Constitutional & administrative law
5
500 - Natural sciences & mathematics
5
540 - Chemistry & allied sciences
5
629 - Other branches of engineering
5
100 - Philosophy & psychology
4
297 - Islam, Babism & Bahai Faith
4
541 - Physical chemistry
4
600 - Technology
4
791 - Public performances
4
943 - Central Europe; Germany
4
140 - Specific philosophical schools
3
200 - Religion
3
304 - Factors affecting social behavior
3
333 - Economics of land & energy
3
364 - Criminology
3
515 - Analysis
3
530 - Physics
3
576 - Genetics & evolution
3
577 - Ecology
3
617 - Surgery & related medical specialties
3
630 - Agriculture & related technologies
3
780 - Music
3
809 - History, description & criticism
3
909 - World history
3
930 - History of ancient world to ca. 499
3
005 - Computer programming, programs & data
2
155 - Differential & developmental psychology
2
190 - Modern western philosophy
2
296 - Judaism
2
more ...