Classification
634 - Orchards, fruits & forestry
316
577 - Ecology
246
630 - Agriculture & related technologies
216
580 - Plants (Botany)
116
571 - Physiology & related subjects
47
333 - Economics of land & energy
27
660 - Chemical engineering
23
581 - Specific topics in natural history
21
910 - Geography & travel
19
579 - Microorganisms, fungi & algae
18
363 - Other social problems & services
15
572 - Biochemistry
15
631 - Techniques, equipment & materials
13
616 - Diseases
12
550 - Earth sciences
11
344 - Labor, social, education & cultural law
9
551 - Geology, hydrology & meteorology
9
590 - Animals (Zoology)
8
641 - Food & drink
8
664 - Food technology
8
576 - Genetics & evolution
7
620 - Engineering & allied operations
5
624 - Civil engineering
5
003 - Systems
4
570 - Life sciences; biology
4
614 - Incidence & prevention of disease
4
338 - Production
3
342 - Constitutional & administrative law
2
371 - Schools & their activities; special education
2
519 - Probabilities & applied mathematics
2
549 - Mineralogy
2
612 - Human physiology
2
621 - Applied physics
2
658 - General management
2
006 - Special computer methods
1
111 - Ontology
1
336 - Public finance
1
500 - Natural sciences & mathematics
1
509 - Historical, geographic & persons treatment
1
530 - Physics
1
539 - Modern physics
1
541 - Physical chemistry
1
543 - Analytical chemistry
1
546 - Inorganic chemistry
1
582 - Plants noted for characteristics & flowers
1
592 - Invertebrates
1
610 - Medicine & health
1
613 - Personal health & safety
1
615 - Pharmacology & therapeutics
1
617 - Surgery & related medical specialties
1
more ...