Classification
330 - Economics
37
658 - General management
26
300 - Social sciences
18
900 - History & geography
17
306 - Culture & institutions
16
320 - Political science
14
700 - The arts; fine & decorative arts
13
363 - Other social problems & services
12
140 - Specific philosophical schools
11
000 - Computer science, information & general works
9
610 - Medicine & health
9
302 - Social interaction
8
100 - Philosophy & psychology
7
301 - Sociology & anthropology
7
305 - Social groups
7
331 - Labor economics
7
338 - Production
7
370 - Education
7
005 - Computer programming, programs & data
6
170 - Ethics
6
333 - Economics of land & energy
6
620 - Engineering & allied operations
6
004 - Data processing & computer science
5
332 - Financial economics
5
381 - Commerce
5
581 - Specific topics in natural history
5
600 - Technology
5
304 - Factors affecting social behavior
4
380 - Commerce, communications & transportation
4
500 - Natural sciences & mathematics
4
791 - Public performances
4
930 - History of ancient world to ca. 499
4
200 - Religion
3
303 - Social processes
3
378 - Higher education
3
613 - Personal health & safety
3
614 - Incidence & prevention of disease
3
150 - Psychology
2
174 - Occupational ethics
2
327 - International relations
2
339 - Macroeconomics & related topics
2
364 - Criminology
2
379 - Public policy issues in education
2
384 - Communications; telecommunication
2
551 - Geology, hydrology & meteorology
2
616 - Diseases
2
630 - Agriculture & related technologies
2
670 - Manufacturing
2
800 - Literature & rhetoric
2
808 - Rhetoric & collections of literature
2
more ...