Classification
303 - Social processes
147
306 - Culture & institutions
44
304 - Factors affecting social behavior
28
302 - Social interaction
16
300 - Social sciences
12
301 - Sociology & anthropology
11
305 - Social groups
9
333 - Economics of land & energy
7
620 - Engineering & allied operations
7
621 - Applied physics
7
006 - Special computer methods
6
361 - Social problems & social welfare in general
6
070 - News media, journalism & publishing
5
320 - Political science
5
004 - Data processing & computer science
3
307 - Communities
3
600 - Technology
3
327 - International relations
2
338 - Production
2
363 - Other social problems & services
2
500 - Natural sciences & mathematics
2
519 - Probabilities & applied mathematics
2
520 - Astronomy & allied sciences
2
551 - Geology, hydrology & meteorology
2
571 - Physiology & related subjects
2
576 - Genetics & evolution
2
601 - Philosophy & theory
2
610 - Medicine & health
2
614 - Incidence & prevention of disease
2
658 - General management
2
005 - Computer programming, programs & data
1
150 - Psychology
1
170 - Ethics
1
330 - Economics
1
364 - Criminology
1
418 - Standard usage & applied linguistics
1
507 - Education, research & related topics
1
509 - Historical, geographic & persons treatment
1
510 - Mathematics
1
530 - Physics
1
570 - Life sciences; biology
1
612 - Human physiology
1
613 - Personal health & safety
1
616 - Diseases
1
628 - Sanitary & municipal engineering
1
629 - Other branches of engineering
1
641 - Food & drink
1
650 - Management & auxiliary services
1
664 - Food technology
1
670 - Manufacturing
1
more ...