Classification
330 - Economics
329
320 - Political science
291
333 - Economics of land & energy
123
972 - Middle America; Mexico
110
900 - History & geography
80
370 - Education
74
363 - Other social problems & services
64
610 - Medicine & health
55
301 - Sociology & anthropology
52
304 - Factors affecting social behavior
49
340 - Law
45
380 - Commerce, communications & transportation
43
600 - Technology
40
700 - The arts; fine & decorative arts
37
305 - Social groups
31
327 - International relations
28
338 - Production
28
000 - Computer science, information & general works
27
820 - English & Old English literatures
23
551 - Geology, hydrology & meteorology
21
620 - Engineering & allied operations
21
140 - Specific philosophical schools
19
331 - Labor economics
16
630 - Agriculture & related technologies
14
300 - Social sciences
13
307 - Communities
12
580 - Plants (Botany)
12
303 - Social processes
11
306 - Culture & institutions
10
336 - Public finance
10
200 - Religion
8
325 - International migration & colonization
8
800 - Literature & rhetoric
8
323 - Civil & political rights
7
382 - International commerce
7
576 - Genetics & evolution
7
930 - History of ancient world to ca. 499
7
339 - Macroeconomics & related topics
6
400 - Language
6
500 - Natural sciences & mathematics
6
581 - Specific topics in natural history
6
720 - Architecture
6
016 - Bibliographies of works on specific subjects
5
332 - Financial economics
5
378 - Higher education
5
410 - Linguistics
5
780 - Music
5
860 - Spanish & Portuguese literatures
5
100 - Philosophy & psychology
4
282 - Roman Catholic Church
4
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