Classification
600 - Technology
3,436
380 - Commerce, communications & transportation
1,974
330 - Economics
771
333 - Economics of land & energy
398
629 - Other branches of engineering
378
320 - Political science
350
620 - Engineering & allied operations
316
700 - The arts; fine & decorative arts
304
363 - Other social problems & services
301
000 - Computer science, information & general works
253
610 - Medicine & health
223
900 - History & geography
223
621 - Applied physics
138
658 - General management
114
388 - Transportation; ground transportation
101
140 - Specific philosophical schools
95
340 - Law
91
500 - Natural sciences & mathematics
88
580 - Plants (Botany)
86
551 - Geology, hydrology & meteorology
79
576 - Genetics & evolution
79
304 - Factors affecting social behavior
76
624 - Civil engineering
47
540 - Chemistry & allied sciences
45
910 - Geography & travel
45
571 - Physiology & related subjects
43
570 - Life sciences; biology
41
530 - Physics
40
612 - Human physiology
39
720 - Architecture
37
006 - Special computer methods
35
414 - Phonology & phonetics
35
630 - Agriculture & related technologies
35
572 - Biochemistry
32
338 - Production
31
004 - Data processing & computer science
30
615 - Pharmacology & therapeutics
26
370 - Education
25
581 - Specific topics in natural history
25
690 - Buildings
23
300 - Social sciences
22
660 - Chemical engineering
21
307 - Communities
19
800 - Literature & rhetoric
19
360 - Social problems & services; associations
17
387 - Water, air & space transportation
17
628 - Sanitary & municipal engineering
16
331 - Labor economics
14
336 - Public finance
14
541 - Physical chemistry
14
more ...