Classification
720 - Architecture
900 - History & geography
21
600 - Technology
20
700 - The arts; fine & decorative arts
20
620 - Engineering & allied operations
18
000 - Computer science, information & general works
14
333 - Economics of land & energy
13
363 - Other social problems & services
12
380 - Commerce, communications & transportation
12
330 - Economics
9
140 - Specific philosophical schools
8
320 - Political science
6
551 - Geology, hydrology & meteorology
6
576 - Genetics & evolution
6
610 - Medicine & health
6
340 - Law
5
580 - Plants (Botany)
5
370 - Education
3
500 - Natural sciences & mathematics
3
414 - Phonology & phonetics
2
800 - Literature & rhetoric
2
400 - Language
1
530 - Physics
1
550 - Earth sciences
1
630 - Agriculture & related technologies
1