Classification
620 - Engineering & allied operations
20,225
600 - Technology
14,503
621 - Applied physics
11,401
005 - Computer programming, programs & data
7,785
004 - Data processing & computer science
5,523
629 - Other branches of engineering
4,470
006 - Special computer methods
3,787
500 - Natural sciences & mathematics
2,671
658 - General management
2,409
900 - History & geography
1,871
624 - Civil engineering
1,800
003 - Systems
1,712
670 - Manufacturing
1,685
333 - Economics of land & energy
1,583
610 - Medicine & health
1,573
519 - Probabilities & applied mathematics
1,532
700 - The arts; fine & decorative arts
1,319
330 - Economics
1,291
363 - Other social problems & services
1,182
000 - Computer science, information & general works
1,092
384 - Communications; telecommunication
1,052
660 - Chemical engineering
996
530 - Physics
918
331 - Labor economics
907
745 - Decorative arts
723
551 - Geology, hydrology & meteorology
631
690 - Buildings
591
380 - Commerce, communications & transportation
520
630 - Agriculture & related technologies
506
515 - Analysis
499
628 - Sanitary & municipal engineering
481
531 - Classical mechanics; solid mechanics
480
320 - Political science
418
518 - Numerical analysis
394
580 - Plants (Botany)
369
338 - Production
353
540 - Chemistry & allied sciences
345
571 - Physiology & related subjects
335
510 - Mathematics
291
140 - Specific philosophical schools
261
550 - Earth sciences
261
720 - Architecture
256
374 - Adult education
255
616 - Diseases
253
300 - Social sciences
231
541 - Physical chemistry
227
576 - Genetics & evolution
226
570 - Life sciences; biology
211
302 - Social interaction
206
520 - Astronomy & allied sciences
199
more ...