Classification
330 - Economics
377
333 - Economics of land & energy
74
610 - Medicine & health
69
338 - Production
57
616 - Diseases
41
363 - Other social problems & services
40
658 - General management
36
304 - Factors affecting social behavior
29
320 - Political science
28
370 - Education
24
005 - Computer programming, programs & data
20
630 - Agriculture & related technologies
19
300 - Social sciences
18
620 - Engineering & allied operations
18
000 - Computer science, information & general works
17
332 - Financial economics
16
613 - Personal health & safety
16
614 - Incidence & prevention of disease
16
331 - Labor economics
15
577 - Ecology
15
004 - Data processing & computer science
14
617 - Surgery & related medical specialties
14
551 - Geology, hydrology & meteorology
12
641 - Food & drink
12
664 - Food technology
12
500 - Natural sciences & mathematics
11
600 - Technology
11
900 - History & geography
11
381 - Commerce
10
618 - Gynecology, obstetrics, pediatrics & geriatrics
10
006 - Special computer methods
9
362 - Social welfare problems & services
9
302 - Social interaction
8
305 - Social groups
8
339 - Macroeconomics & related topics
8
570 - Life sciences; biology
8
581 - Specific topics in natural history
8
650 - Management & auxiliary services
8
700 - The arts; fine & decorative arts
8
301 - Sociology & anthropology
7
306 - Culture & institutions
7
307 - Communities
7
337 - International economics
7
576 - Genetics & evolution
7
580 - Plants (Botany)
7
001 - Knowledge
6
380 - Commerce, communications & transportation
6
571 - Physiology & related subjects
6
612 - Human physiology
6
615 - Pharmacology & therapeutics
6
more ...