Classification
660 - Chemical engineering
631 - Techniques, equipment & materials
15
600 - Technology
4
620 - Engineering & allied operations
4
628 - Sanitary & municipal engineering
3
363 - Other social problems & services
2
170 - Ethics
1
361 - Social problems & social welfare in general
1
370 - Education
1
540 - Chemistry & allied sciences
1
547 - Organic chemistry
1
610 - Medicine & health
1