Classification
330 - Economics
600 - Technology
333 - Economics of land & energy
424
620 - Engineering & allied operations
368
700 - The arts; fine & decorative arts
348
900 - History & geography
273
363 - Other social problems & services
267
320 - Political science
252
000 - Computer science, information & general works
221
610 - Medicine & health
164
380 - Commerce, communications & transportation
149
370 - Education
110
580 - Plants (Botany)
93
630 - Agriculture & related technologies
93
140 - Specific philosophical schools
92
658 - General management
88
551 - Geology, hydrology & meteorology
69
304 - Factors affecting social behavior
59
576 - Genetics & evolution
58
500 - Natural sciences & mathematics
48
300 - Social sciences
43
581 - Specific topics in natural history
40
340 - Law
39
720 - Architecture
39
100 - Philosophy & psychology
30
800 - Literature & rhetoric
29
400 - Language
23
170 - Ethics
19
540 - Chemistry & allied sciences
19
780 - Music
15
657 - Accounting
14
200 - Religion
12
338 - Production
12
530 - Physics
12
336 - Public finance
11
414 - Phonology & phonetics
11
410 - Linguistics
10
005 - Computer programming, programs & data
9
301 - Sociology & anthropology
9
350 - Public administration & military science
8
361 - Social problems & social welfare in general
7
651 - Office services
7
331 - Labor economics
5
615 - Pharmacology & therapeutics
5
770 - Photography, photographs & computer art
5
791 - Public performances
5
302 - Social interaction
4
332 - Financial economics
4
381 - Commerce
4
384 - Communications; telecommunication
4
more ...