Classification
530 - Physics
620 - Engineering & allied operations
700 - The arts; fine & decorative arts
600 - Technology
27
333 - Economics of land & energy
21
900 - History & geography
20
000 - Computer science, information & general works
18
380 - Commerce, communications & transportation
7
500 - Natural sciences & mathematics
7
330 - Economics
6
540 - Chemistry & allied sciences
6
340 - Law
5
363 - Other social problems & services
5
551 - Geology, hydrology & meteorology
5
300 - Social sciences
4
320 - Political science
4
370 - Education
4
610 - Medicine & health
4
100 - Philosophy & psychology
3
576 - Genetics & evolution
3
720 - Architecture
3
140 - Specific philosophical schools
2
400 - Language
2
414 - Phonology & phonetics
2
580 - Plants (Botany)
2
630 - Agriculture & related technologies
2
800 - Literature & rhetoric
2
170 - Ethics
1
200 - Religion
1
301 - Sociology & anthropology
1
410 - Linguistics
1
550 - Earth sciences
1
581 - Specific topics in natural history
1
658 - General management
1
770 - Photography, photographs & computer art
1
780 - Music
1