Classification
331 - Labor economics
206
330 - Economics
203
380 - Commerce, communications & transportation
98
332 - Financial economics
50
301 - Sociology & anthropology
27
600 - Technology
26
370 - Education
21
100 - Philosophy & psychology
13
304 - Factors affecting social behavior
13
500 - Natural sciences & mathematics
13
610 - Medicine & health
12
340 - Law
10
336 - Public finance
8
364 - Criminology
7
630 - Agriculture & related technologies
7
320 - Political science
6
510 - Mathematics
6
297 - Islam, Babism & Bahai Faith
4
388 - Transportation; ground transportation
4
335 - Socialism & related systems
3
570 - Life sciences; biology
3
621 - Applied physics
3
640 - Home & family management
3
780 - Music
2
110 - Metaphysics
1
170 - Ethics
1
200 - Religion
1
310 - Collections of general statistics
1
341 - Law of nations
1
350 - Public administration & military science
1
360 - Social problems & services; associations
1
390 - Customs, etiquette & folklore
1
530 - Physics
1
622 - Mining & related operations
1
625 - Engineering of railroads & roads
1
910 - Geography & travel
1