Classification
581 - Specific topics in natural history
363 - Other social problems & services
28
330 - Economics
15
100 - Philosophy & psychology
13
140 - Specific philosophical schools
13
320 - Political science
12
333 - Economics of land & energy
12
580 - Plants (Botany)
12
900 - History & geography
12
600 - Technology
11
551 - Geology, hydrology & meteorology
8
700 - The arts; fine & decorative arts
7
200 - Religion
6
620 - Engineering & allied operations
6
630 - Agriculture & related technologies
5
610 - Medicine & health
4
300 - Social sciences
3
340 - Law
3
590 - Animals (Zoology)
3
170 - Ethics
2
304 - Factors affecting social behavior
2
500 - Natural sciences & mathematics
2
576 - Genetics & evolution
2
791 - Public performances
2
301 - Sociology & anthropology
1
370 - Education
1
380 - Commerce, communications & transportation
1
410 - Linguistics
1
540 - Chemistry & allied sciences
1
612 - Human physiology
1
780 - Music
1
800 - Literature & rhetoric
1