Classification
600 - Technology
500 - Natural sciences & mathematics
13,131
620 - Engineering & allied operations
2,930
900 - History & geography
2,010
700 - The arts; fine & decorative arts
1,951
333 - Economics of land & energy
1,661
330 - Economics
1,499
000 - Computer science, information & general works
1,255
363 - Other social problems & services
1,058
610 - Medicine & health
919
380 - Commerce, communications & transportation
766
320 - Political science
700
630 - Agriculture & related technologies
537
370 - Education
465
580 - Plants (Botany)
447
140 - Specific philosophical schools
443
540 - Chemistry & allied sciences
344
300 - Social sciences
306
576 - Genetics & evolution
306
551 - Geology, hydrology & meteorology
220
658 - General management
220
304 - Factors affecting social behavior
198
100 - Philosophy & psychology
189
340 - Law
181
720 - Architecture
169
581 - Specific topics in natural history
149
800 - Literature & rhetoric
138
414 - Phonology & phonetics
131
530 - Physics
124
400 - Language
118
005 - Computer programming, programs & data
110
170 - Ethics
108
301 - Sociology & anthropology
75
331 - Labor economics
65
410 - Linguistics
59
629 - Other branches of engineering
51
200 - Religion
48
612 - Human physiology
47
780 - Music
42
361 - Social problems & social welfare in general
32
004 - Data processing & computer science
30
615 - Pharmacology & therapeutics
30
338 - Production
29
336 - Public finance
26
657 - Accounting
23
770 - Photography, photographs & computer art
20
120 - Epistemology, causation & humankind
17
621 - Applied physics
17
670 - Manufacturing
17
364 - Criminology
14
more ...