Classification
005 - Computer programming, programs & data
33
006 - Special computer methods
15
330 - Economics
11
500 - Natural sciences & mathematics
11
331 - Labor economics
10
320 - Political science
9
370 - Education
9
000 - Computer science, information & general works
7
610 - Medicine & health
7
616 - Diseases
6
306 - Culture & institutions
5
620 - Engineering & allied operations
5
004 - Data processing & computer science
4
100 - Philosophy & psychology
4
600 - Technology
4
658 - General management
4
300 - Social sciences
3
304 - Factors affecting social behavior
3
363 - Other social problems & services
3
745 - Decorative arts
3
140 - Specific philosophical schools
2
170 - Ethics
2
327 - International relations
2
333 - Economics of land & energy
2
338 - Production
2
384 - Communications; telecommunication
2
400 - Language
2
410 - Linguistics
2
530 - Physics
2
580 - Plants (Botany)
2
630 - Agriculture & related technologies
2
664 - Food technology
2
700 - The arts; fine & decorative arts
2
791 - Public performances
2
900 - History & geography
2
003 - Systems
1
155 - Differential & developmental psychology
1
297 - Islam, Babism & Bahai Faith
1
301 - Sociology & anthropology
1
303 - Social processes
1
322 - Relation of state to organized groups
1
340 - Law
1
342 - Constitutional & administrative law
1
362 - Social welfare problems & services
1
371 - Schools & their activities; special education
1
380 - Commerce, communications & transportation
1
387 - Water, air & space transportation
1
418 - Standard usage & applied linguistics
1
507 - Education, research & related topics
1
512 - Algebra
1
more ...