Classification
620 - Engineering & allied operations
1,831
530 - Physics
260
621 - Applied physics
215
700 - The arts; fine & decorative arts
190
600 - Technology
189
531 - Classical mechanics; solid mechanics
167
541 - Physical chemistry
147
670 - Manufacturing
138
000 - Computer science, information & general works
127
333 - Economics of land & energy
115
900 - History & geography
108
610 - Medicine & health
81
660 - Chemical engineering
80
543 - Analytical chemistry
77
363 - Other social problems & services
73
546 - Inorganic chemistry
61
540 - Chemistry & allied sciences
60
580 - Plants (Botany)
59
330 - Economics
43
537 - Electricity & electronics
38
140 - Specific philosophical schools
36
576 - Genetics & evolution
35
691 - Building materials
35
539 - Modern physics
33
380 - Commerce, communications & transportation
29
414 - Phonology & phonetics
29
500 - Natural sciences & mathematics
23
548 - Crystallography
21
629 - Other branches of engineering
21
536 - Heat
20
547 - Organic chemistry
20
624 - Civil engineering
20
538 - Magnetism
17
340 - Law
14
549 - Mineralogy
14
571 - Physiology & related subjects
14
304 - Factors affecting social behavior
13
519 - Probabilities & applied mathematics
13
630 - Agriculture & related technologies
13
551 - Geology, hydrology & meteorology
12
667 - Cleaning, color & coating technologies
11
534 - Sound & related vibrations
10
800 - Literature & rhetoric
10
572 - Biochemistry
9
628 - Sanitary & municipal engineering
8
690 - Buildings
8
570 - Life sciences; biology
7
664 - Food technology
7
535 - Light & infrared & ultraviolet phenomena
6
641 - Food & drink
6
more ...