Classification
307 - Communities
162
304 - Factors affecting social behavior
50
333 - Economics of land & energy
19
910 - Geography & travel
19
338 - Production
14
363 - Other social problems & services
10
621 - Applied physics
9
629 - Other branches of engineering
8
577 - Ecology
7
300 - Social sciences
6
551 - Geology, hydrology & meteorology
6
710 - Civic & landscape art
6
720 - Architecture
6
004 - Data processing & computer science
4
005 - Computer programming, programs & data
3
006 - Special computer methods
3
301 - Sociology & anthropology
3
306 - Culture & institutions
3
320 - Political science
3
624 - Civil engineering
3
628 - Sanitary & municipal engineering
3
658 - General management
3
660 - Chemical engineering
3
690 - Buildings
3
330 - Economics
2
344 - Labor, social, education & cultural law
2
388 - Transportation; ground transportation
2
613 - Personal health & safety
2
620 - Engineering & allied operations
2
630 - Agriculture & related technologies
2
700 - The arts; fine & decorative arts
2
003 - Systems
1
140 - Specific philosophical schools
1
150 - Psychology
1
303 - Social processes
1
305 - Social groups
1
350 - Public administration & military science
1
355 - Military science
1
361 - Social problems & social welfare in general
1
384 - Communications; telecommunication
1
520 - Astronomy & allied sciences
1
600 - Technology
1
614 - Incidence & prevention of disease
1
631 - Techniques, equipment & materials
1
711 - Area planning
1