Classification
620 - Engineering & allied operations
380 - Commerce, communications & transportation
248
600 - Technology
212
900 - History & geography
173
700 - The arts; fine & decorative arts
135
333 - Economics of land & energy
117
363 - Other social problems & services
71
000 - Computer science, information & general works
65
330 - Economics
45
140 - Specific philosophical schools
34
500 - Natural sciences & mathematics
33
576 - Genetics & evolution
32
610 - Medicine & health
32
580 - Plants (Botany)
29
551 - Geology, hydrology & meteorology
27
658 - General management
24
320 - Political science
17
630 - Agriculture & related technologies
16
720 - Architecture
15
340 - Law
13
414 - Phonology & phonetics
12
540 - Chemistry & allied sciences
11
370 - Education
10
629 - Other branches of engineering
10
304 - Factors affecting social behavior
8
530 - Physics
7
800 - Literature & rhetoric
7
581 - Specific topics in natural history
6
612 - Human physiology
6
621 - Applied physics
6
400 - Language
5
300 - Social sciences
4
100 - Philosophy & psychology
3
410 - Linguistics
3
550 - Earth sciences
3
745 - Decorative arts
3
004 - Data processing & computer science
2
338 - Production
2
361 - Social problems & social welfare in general
2
381 - Commerce
2
384 - Communications; telecommunication
2
660 - Chemical engineering
2
001 - Knowledge
1
120 - Epistemology, causation & humankind
1
170 - Ethics
1
200 - Religion
1
331 - Labor economics
1
387 - Water, air & space transportation
1
388 - Transportation; ground transportation
1
615 - Pharmacology & therapeutics
1
more ...