Classification
620 - Engineering & allied operations
19,980
600 - Technology
13,911
621 - Applied physics
11,346
005 - Computer programming, programs & data
7,750
004 - Data processing & computer science
5,525
629 - Other branches of engineering
4,455
006 - Special computer methods
3,672
500 - Natural sciences & mathematics
2,646
658 - General management
2,393
900 - History & geography
1,867
624 - Civil engineering
1,794
003 - Systems
1,703
670 - Manufacturing
1,671
519 - Probabilities & applied mathematics
1,571
610 - Medicine & health
1,547
333 - Economics of land & energy
1,520
700 - The arts; fine & decorative arts
1,267
330 - Economics
1,266
363 - Other social problems & services
1,137
000 - Computer science, information & general works
1,069
384 - Communications; telecommunication
1,051
660 - Chemical engineering
1,019
530 - Physics
922
331 - Labor economics
904
745 - Decorative arts
723
551 - Geology, hydrology & meteorology
619
690 - Buildings
597
380 - Commerce, communications & transportation
516
515 - Analysis
516
531 - Classical mechanics; solid mechanics
497
628 - Sanitary & municipal engineering
481
630 - Agriculture & related technologies
399
320 - Political science
397
518 - Numerical analysis
397
580 - Plants (Botany)
354
338 - Production
349
571 - Physiology & related subjects
336
510 - Mathematics
290
616 - Diseases
272
540 - Chemistry & allied sciences
266
550 - Earth sciences
260
140 - Specific philosophical schools
259
374 - Adult education
255
720 - Architecture
250
541 - Physical chemistry
231
576 - Genetics & evolution
223
300 - Social sciences
214
570 - Life sciences; biology
212
302 - Social interaction
202
520 - Astronomy & allied sciences
200
more ...