Classification
900 - History & geography
610 - Medicine & health
127
100 - Philosophy & psychology
16
320 - Political science
15
300 - Social sciences
14
170 - Ethics
7
200 - Religion
7
600 - Technology
6
140 - Specific philosophical schools
5
370 - Education
5
500 - Natural sciences & mathematics
5
330 - Economics
4
361 - Social problems & social welfare in general
4
700 - The arts; fine & decorative arts
4
340 - Law
3
363 - Other social problems & services
3
380 - Commerce, communications & transportation
3
580 - Plants (Botany)
3
581 - Specific topics in natural history
3
301 - Sociology & anthropology
2
333 - Economics of land & energy
2
362 - Social welfare problems & services
2
551 - Geology, hydrology & meteorology
2
576 - Genetics & evolution
2
620 - Engineering & allied operations
2
791 - Public performances
2
800 - Literature & rhetoric
2
120 - Epistemology, causation & humankind
1
297 - Islam, Babism & Bahai Faith
1
400 - Language
1
410 - Linguistics
1
540 - Chemistry & allied sciences
1
612 - Human physiology
1
770 - Photography, photographs & computer art
1