Classification
006 - Special computer methods
7
616 - Diseases
7
005 - Computer programming, programs & data
5
306 - Culture & institutions
5
515 - Analysis
5
370 - Education
4
371 - Schools & their activities; special education
4
510 - Mathematics
4
004 - Data processing & computer science
3
304 - Factors affecting social behavior
3
519 - Probabilities & applied mathematics
3
551 - Geology, hydrology & meteorology
3
808 - Rhetoric & collections of literature
3
910 - Geography & travel
3
200 - Religion
2
210 - Philosophy & theory of religion
2
300 - Social sciences
2
320 - Political science
2
333 - Economics of land & energy
2
338 - Production
2
401 - Philosophy & theory
2
516 - Geometry
2
579 - Microorganisms, fungi & algae
2
620 - Engineering & allied operations
2
621 - Applied physics
2
109 - Historical & collected persons treatment
1
126 - The self
1
140 - Specific philosophical schools
1
142 - Critical philosophy
1
149 - Other philosophical systems
1
150 - Psychology
1
155 - Differential & developmental psychology
1
170 - Ethics
1
174 - Occupational ethics
1
190 - Modern western philosophy
1
230 - Christianity & Christian theology
1
301 - Sociology & anthropology
1
305 - Social groups
1
322 - Relation of state to organized groups
1
327 - International relations
1
330 - Economics
1
332 - Financial economics
1
361 - Social problems & social welfare in general
1
363 - Other social problems & services
1
379 - Public policy issues in education
1
500 - Natural sciences & mathematics
1
520 - Astronomy & allied sciences
1
526 - Mathematical geography
1
530 - Physics
1
550 - Earth sciences
1
more ...