Classification
530 - Physics
333 - Economics of land & energy
33
620 - Engineering & allied operations
24
000 - Computer science, information & general works
5
370 - Education
5
700 - The arts; fine & decorative arts
5
100 - Philosophy & psychology
4
900 - History & geography
4
140 - Specific philosophical schools
3
200 - Religion
3
320 - Political science
3
363 - Other social problems & services
3
380 - Commerce, communications & transportation
3
500 - Natural sciences & mathematics
3
520 - Astronomy & allied sciences
3
539 - Modern physics
3
576 - Genetics & evolution
3
330 - Economics
2
340 - Law
2
540 - Chemistry & allied sciences
2
600 - Technology
2
300 - Social sciences
1
301 - Sociology & anthropology
1
400 - Language
1
551 - Geology, hydrology & meteorology
1