Classification
616 - Diseases
47
579 - Microorganisms, fungi & algae
24
580 - Plants (Botany)
11
333 - Economics of land & energy
8
581 - Specific topics in natural history
8
617 - Surgery & related medical specialties
8
577 - Ecology
6
363 - Other social problems & services
4
610 - Medicine & health
4
572 - Biochemistry
3
618 - Gynecology, obstetrics, pediatrics & geriatrics
3
660 - Chemical engineering
3
670 - Manufacturing
3
003 - Systems
2
304 - Factors affecting social behavior
2
547 - Organic chemistry
2
550 - Earth sciences
2
571 - Physiology & related subjects
2
621 - Applied physics
2
624 - Civil engineering
2
631 - Techniques, equipment & materials
2
634 - Orchards, fruits & forestry
2
658 - General management
2
005 - Computer programming, programs & data
1
306 - Culture & institutions
1
320 - Political science
1
338 - Production
1
372 - Elementary education
1
500 - Natural sciences & mathematics
1
509 - Historical, geographic & persons treatment
1
520 - Astronomy & allied sciences
1
541 - Physical chemistry
1
546 - Inorganic chemistry
1
551 - Geology, hydrology & meteorology
1
570 - Life sciences; biology
1
576 - Genetics & evolution
1
599 - Mammals
1
611 - Human anatomy, cytology & histology
1
613 - Personal health & safety
1
650 - Management & auxiliary services
1
657 - Accounting
1
910 - Geography & travel
1