Classification
551 - Geology, hydrology & meteorology
363 - Other social problems & services
40
320 - Political science
23
330 - Economics
19
333 - Economics of land & energy
17
600 - Technology
15
140 - Specific philosophical schools
11
581 - Specific topics in natural history
11
300 - Social sciences
10
620 - Engineering & allied operations
10
900 - History & geography
9
700 - The arts; fine & decorative arts
7
100 - Philosophy & psychology
6
340 - Law
4
610 - Medicine & health
4
200 - Religion
3
304 - Factors affecting social behavior
3
370 - Education
3
380 - Commerce, communications & transportation
3
720 - Architecture
3
500 - Natural sciences & mathematics
2
576 - Genetics & evolution
2
590 - Animals (Zoology)
2
630 - Agriculture & related technologies
2
120 - Epistemology, causation & humankind
1
170 - Ethics
1
301 - Sociology & anthropology
1
350 - Public administration & military science
1
360 - Social problems & services; associations
1
361 - Social problems & social welfare in general
1
410 - Linguistics
1
414 - Phonology & phonetics
1
530 - Physics
1
540 - Chemistry & allied sciences
1
550 - Earth sciences
1
580 - Plants (Botany)
1
780 - Music
1
800 - Literature & rhetoric
1