Classification
900 - History & geography
178
320 - Political science
82
700 - The arts; fine & decorative arts
81
300 - Social sciences
74
363 - Other social problems & services
67
301 - Sociology & anthropology
63
330 - Economics
58
140 - Specific philosophical schools
57
200 - Religion
54
333 - Economics of land & energy
54
000 - Computer science, information & general works
45
610 - Medicine & health
38
340 - Law
33
304 - Factors affecting social behavior
32
370 - Education
30
100 - Philosophy & psychology
27
400 - Language
24
551 - Geology, hydrology & meteorology
24
581 - Specific topics in natural history
24
580 - Plants (Botany)
20
800 - Literature & rhetoric
20
600 - Technology
18
410 - Linguistics
15
305 - Social groups
14
630 - Agriculture & related technologies
13
170 - Ethics
12
576 - Genetics & evolution
10
380 - Commerce, communications & transportation
9
398 - Folklore
9
780 - Music
9
620 - Engineering & allied operations
8
720 - Architecture
8
341 - Law of nations
6
346 - Private law
6
361 - Social problems & social welfare in general
5
500 - Natural sciences & mathematics
5
297 - Islam, Babism & Bahai Faith
4
342 - Constitutional & administrative law
4
364 - Criminology
4
540 - Chemistry & allied sciences
4
658 - General management
4
120 - Epistemology, causation & humankind
3
338 - Production
3
414 - Phonology & phonetics
3
520 - Astronomy & allied sciences
3
972 - Middle America; Mexico
3
994 - Australia
3
323 - Civil & political rights
2
350 - Public administration & military science
2
360 - Social problems & services; associations
2
more ...