Classification
600 - Technology
3,618
380 - Commerce, communications & transportation
2,008
330 - Economics
1,292
629 - Other branches of engineering
412
333 - Economics of land & energy
404
320 - Political science
357
620 - Engineering & allied operations
320
700 - The arts; fine & decorative arts
309
363 - Other social problems & services
307
000 - Computer science, information & general works
255
900 - History & geography
230
610 - Medicine & health
226
621 - Applied physics
140
658 - General management
119
140 - Specific philosophical schools
99
340 - Law
96
500 - Natural sciences & mathematics
89
580 - Plants (Botany)
86
388 - Transportation; ground transportation
80
551 - Geology, hydrology & meteorology
80
304 - Factors affecting social behavior
79
576 - Genetics & evolution
79
624 - Civil engineering
51
540 - Chemistry & allied sciences
50
571 - Physiology & related subjects
48
910 - Geography & travel
46
570 - Life sciences; biology
43
530 - Physics
41
612 - Human physiology
39
630 - Agriculture & related technologies
39
720 - Architecture
39
006 - Special computer methods
37
414 - Phonology & phonetics
35
572 - Biochemistry
34
338 - Production
31
004 - Data processing & computer science
28
300 - Social sciences
26
370 - Education
26
581 - Specific topics in natural history
26
615 - Pharmacology & therapeutics
26
690 - Buildings
24
660 - Chemical engineering
21
307 - Communities
20
800 - Literature & rhetoric
19
360 - Social problems & services; associations
17
387 - Water, air & space transportation
17
628 - Sanitary & municipal engineering
17
691 - Building materials
15
331 - Labor economics
14
336 - Public finance
14
more ...