Classification
660 - Chemical engineering
68
620 - Engineering & allied operations
59
540 - Chemistry & allied sciences
43
547 - Organic chemistry
35
621 - Applied physics
20
541 - Physical chemistry
19
363 - Other social problems & services
18
628 - Sanitary & municipal engineering
15
000 - Computer science, information & general works
14
333 - Economics of land & energy
14
700 - The arts; fine & decorative arts
14
600 - Technology
13
577 - Ecology
12
610 - Medicine & health
9
330 - Economics
7
580 - Plants (Botany)
7
500 - Natural sciences & mathematics
6
304 - Factors affecting social behavior
5
530 - Physics
5
631 - Techniques, equipment & materials
5
630 - Agriculture & related technologies
4
546 - Inorganic chemistry
3
572 - Biochemistry
3
576 - Genetics & evolution
3
668 - Technology of other organic products
3
670 - Manufacturing
3
140 - Specific philosophical schools
2
414 - Phonology & phonetics
2
543 - Analytical chemistry
2
615 - Pharmacology & therapeutics
2
641 - Food & drink
2
664 - Food technology
2
370 - Education
1
378 - Higher education
1
551 - Geology, hydrology & meteorology
1
632 - Plant injuries, diseases & pests
1
658 - General management
1
662 - Explosives, fuels & related products
1
667 - Cleaning, color & coating technologies
1
674 - Lumber processing, wood products & cork
1
691 - Building materials
1
900 - History & geography
1