Classification
900 - History & geography
320 - Political science
4,453
330 - Economics
4,264
600 - Technology
1,806
620 - Engineering & allied operations
1,716
700 - The arts; fine & decorative arts
1,661
300 - Social sciences
868
333 - Economics of land & energy
824
800 - Literature & rhetoric
706
576 - Genetics & evolution
556
363 - Other social problems & services
509
140 - Specific philosophical schools
493
610 - Medicine & health
477
340 - Law
463
000 - Computer science, information & general works
420
380 - Commerce, communications & transportation
420
200 - Religion
401
100 - Philosophy & psychology
397
301 - Sociology & anthropology
298
400 - Language
251
580 - Plants (Botany)
209
370 - Education
206
410 - Linguistics
201
720 - Architecture
173
630 - Agriculture & related technologies
140
551 - Geology, hydrology & meteorology
131
780 - Music
131
500 - Natural sciences & mathematics
119
304 - Factors affecting social behavior
104
297 - Islam, Babism & Bahai Faith
102
414 - Phonology & phonetics
100
530 - Physics
95
170 - Ethics
93
581 - Specific topics in natural history
92
791 - Public performances
80
540 - Chemistry & allied sciences
70
658 - General management
53
296 - Judaism
52
770 - Photography, photographs & computer art
47
361 - Social problems & social welfare in general
32
120 - Epistemology, causation & humankind
28
398 - Folklore
26
160 - Logic
20
612 - Human physiology
18
920 - Biography, genealogy & insignia
16
350 - Public administration & military science
14
550 - Earth sciences
11
520 - Astronomy & allied sciences
10
615 - Pharmacology & therapeutics
10
657 - Accounting
9
more ...