Classification
330 - Economics
320 - Political science
281
380 - Commerce, communications & transportation
229
363 - Other social problems & services
119
333 - Economics of land & energy
114
600 - Technology
73
700 - The arts; fine & decorative arts
68
900 - History & geography
66
000 - Computer science, information & general works
57
340 - Law
47
620 - Engineering & allied operations
45
610 - Medicine & health
35
658 - General management
34
551 - Geology, hydrology & meteorology
26
500 - Natural sciences & mathematics
24
140 - Specific philosophical schools
23
576 - Genetics & evolution
17
370 - Education
16
300 - Social sciences
14
630 - Agriculture & related technologies
14
304 - Factors affecting social behavior
13
580 - Plants (Botany)
12
388 - Transportation; ground transportation
10
800 - Literature & rhetoric
9
720 - Architecture
8
530 - Physics
7
384 - Communications; telecommunication
6
004 - Data processing & computer science
5
414 - Phonology & phonetics
5
336 - Public finance
4
410 - Linguistics
4
581 - Specific topics in natural history
4
657 - Accounting
4
361 - Social problems & social welfare in general
3
808 - Rhetoric & collections of literature
3
170 - Ethics
2
200 - Religion
2
302 - Social interaction
2
331 - Labor economics
2
381 - Commerce
2
387 - Water, air & space transportation
2
400 - Language
2
540 - Chemistry & allied sciences
2
650 - Management & auxiliary services
2
670 - Manufacturing
2
011 - Bibliographies
1
158 - Applied psychology
1
160 - Logic
1
297 - Islam, Babism & Bahai Faith
1
301 - Sociology & anthropology
1
more ...