Classification
507 - Education, research & related topics
258
370 - Education
217
371 - Schools & their activities; special education
59
500 - Natural sciences & mathematics
54
530 - Physics
42
005 - Computer programming, programs & data
38
540 - Chemistry & allied sciences
36
600 - Technology
36
333 - Economics of land & energy
35
006 - Special computer methods
34
004 - Data processing & computer science
31
610 - Medicine & health
31
620 - Engineering & allied operations
30
300 - Social sciences
28
621 - Applied physics
26
510 - Mathematics
23
304 - Factors affecting social behavior
20
700 - The arts; fine & decorative arts
20
378 - Higher education
19
330 - Economics
18
303 - Social processes
16
306 - Culture & institutions
16
400 - Language
15
000 - Computer science, information & general works
14
100 - Philosophy & psychology
14
363 - Other social problems & services
14
320 - Political science
11
501 - Philosophy & theory
11
570 - Life sciences; biology
11
900 - History & geography
11
520 - Astronomy & allied sciences
10
551 - Geology, hydrology & meteorology
10
658 - General management
10
910 - Geography & travel
10
140 - Specific philosophical schools
9
380 - Commerce, communications & transportation
9
650 - Management & auxiliary services
8
001 - Knowledge
7
340 - Law
7
531 - Classical mechanics; solid mechanics
7
641 - Food & drink
7
660 - Chemical engineering
7
664 - Food technology
7
003 - Systems
6
153 - Mental processes & intelligence
6
302 - Social interaction
6
305 - Social groups
6
612 - Human physiology
6
020 - Library & information sciences
5
372 - Elementary education
5
more ...