Classification
363 - Other social problems & services
5
628 - Sanitary & municipal engineering
5
333 - Economics of land & energy
4
600 - Technology
4
620 - Engineering & allied operations
4
900 - History & geography
3
540 - Chemistry & allied sciences
2
700 - The arts; fine & decorative arts
2
140 - Specific philosophical schools
1
500 - Natural sciences & mathematics
1
551 - Geology, hydrology & meteorology
1
610 - Medicine & health
1
614 - Incidence & prevention of disease
1