Classification
620 - Engineering & allied operations
600 - Technology
2,815
500 - Natural sciences & mathematics
2,480
900 - History & geography
1,839
005 - Computer programming, programs & data
1,805
700 - The arts; fine & decorative arts
1,208
621 - Applied physics
1,082
658 - General management
1,061
333 - Economics of land & energy
1,047
000 - Computer science, information & general works
979
384 - Communications; telecommunication
931
330 - Economics
842
331 - Labor economics
832
363 - Other social problems & services
746
745 - Decorative arts
738
380 - Commerce, communications & transportation
499
610 - Medicine & health
461
004 - Data processing & computer science
354
630 - Agriculture & related technologies
338
006 - Special computer methods
327
580 - Plants (Botany)
323
140 - Specific philosophical schools
252
530 - Physics
244
629 - Other branches of engineering
210
576 - Genetics & evolution
198
302 - Social interaction
194
540 - Chemistry & allied sciences
190
300 - Social sciences
172
338 - Production
160
551 - Geology, hydrology & meteorology
160
510 - Mathematics
157
720 - Architecture
156
374 - Adult education
149
320 - Political science
140
770 - Photography, photographs & computer art
139
370 - Education
112
340 - Law
106
670 - Manufacturing
95
414 - Phonology & phonetics
93
581 - Specific topics in natural history
76
800 - Literature & rhetoric
76
667 - Cleaning, color & coating technologies
75
781 - General principles & musical forms
69
660 - Chemical engineering
66
381 - Commerce
63
400 - Language
63
100 - Philosophy & psychology
61
681 - Precision instruments & other devices
51
304 - Factors affecting social behavior
50
001 - Knowledge
43
more ...