Classification
600 - Technology
620 - Engineering & allied operations
2,713
700 - The arts; fine & decorative arts
1,843
900 - History & geography
1,838
333 - Economics of land & energy
1,567
330 - Economics
1,260
000 - Computer science, information & general works
1,158
363 - Other social problems & services
987
610 - Medicine & health
825
380 - Commerce, communications & transportation
705
320 - Political science
525
630 - Agriculture & related technologies
466
580 - Plants (Botany)
439
140 - Specific philosophical schools
399
370 - Education
356
540 - Chemistry & allied sciences
333
576 - Genetics & evolution
301
500 - Natural sciences & mathematics
279
551 - Geology, hydrology & meteorology
212
658 - General management
200
300 - Social sciences
183
340 - Law
166
304 - Factors affecting social behavior
151
720 - Architecture
151
100 - Philosophy & psychology
139
581 - Specific topics in natural history
136
414 - Phonology & phonetics
131
800 - Literature & rhetoric
126
530 - Physics
111
400 - Language
101
005 - Computer programming, programs & data
91
170 - Ethics
89
331 - Labor economics
59
301 - Sociology & anthropology
56
410 - Linguistics
55
629 - Other branches of engineering
50
612 - Human physiology
45
200 - Religion
37
780 - Music
36
361 - Social problems & social welfare in general
31
615 - Pharmacology & therapeutics
30
004 - Data processing & computer science
26
338 - Production
26
336 - Public finance
20
657 - Accounting
20
770 - Photography, photographs & computer art
19
621 - Applied physics
17
670 - Manufacturing
15
364 - Criminology
12
384 - Communications; telecommunication
12
more ...