Classification
551 - Geology, hydrology & meteorology
255
577 - Ecology
41
550 - Earth sciences
29
621 - Applied physics
13
333 - Economics of land & energy
12
910 - Geography & travel
12
526 - Mathematical geography
10
531 - Classical mechanics; solid mechanics
8
534 - Sound & related vibrations
7
363 - Other social problems & services
5
549 - Mineralogy
5
620 - Engineering & allied operations
4
628 - Sanitary & municipal engineering
3
629 - Other branches of engineering
3
560 - Paleontology; paleozoology
2
590 - Animals (Zoology)
2
624 - Civil engineering
2
003 - Systems
1
519 - Probabilities & applied mathematics
1
530 - Physics
1
570 - Life sciences; biology
1
571 - Physiology & related subjects
1
573 - Specific physiological systems in animals
1
579 - Microorganisms, fungi & algae
1
690 - Buildings
1