Classification
307 - Communities
434
304 - Factors affecting social behavior
399
333 - Economics of land & energy
100
577 - Ecology
77
910 - Geography & travel
71
306 - Culture & institutions
52
338 - Production
48
330 - Economics
45
320 - Political science
40
305 - Social groups
34
720 - Architecture
34
629 - Other branches of engineering
28
363 - Other social problems & services
27
690 - Buildings
26
621 - Applied physics
24
624 - Civil engineering
24
551 - Geology, hydrology & meteorology
21
658 - General management
20
710 - Civic & landscape art
19
628 - Sanitary & municipal engineering
15
630 - Agriculture & related technologies
15
006 - Special computer methods
13
033 - Encyclopedias in other Germanic languages
12
361 - Social problems & social welfare in general
12
613 - Personal health & safety
11
696 - Utilities
11
003 - Systems
10
809 - History, description & criticism
10
090 - Manuscripts & rare books
9
301 - Sociology & anthropology
9
550 - Earth sciences
9
302 - Social interaction
8
364 - Criminology
7
660 - Chemical engineering
7
303 - Social processes
6
004 - Data processing & computer science
5
300 - Social sciences
5
339 - Macroeconomics & related topics
5
614 - Incidence & prevention of disease
5
005 - Computer programming, programs & data
4
331 - Labor economics
4
351 - Public administration
4
500 - Natural sciences & mathematics
4
610 - Medicine & health
4
631 - Techniques, equipment & materials
4
634 - Orchards, fruits & forestry
4
670 - Manufacturing
4
711 - Area planning
4
327 - International relations
3
344 - Labor, social, education & cultural law
3
more ...