Classification
333 - Economics of land & energy
242
621 - Applied physics
220
600 - Technology
191
620 - Engineering & allied operations
177
330 - Economics
150
700 - The arts; fine & decorative arts
117
900 - History & geography
104
363 - Other social problems & services
97
000 - Computer science, information & general works
92
551 - Geology, hydrology & meteorology
79
662 - Explosives, fuels & related products
66
380 - Commerce, communications & transportation
54
660 - Chemical engineering
48
540 - Chemistry & allied sciences
45
580 - Plants (Botany)
34
610 - Medicine & health
28
320 - Political science
27
500 - Natural sciences & mathematics
27
576 - Genetics & evolution
27
530 - Physics
25
624 - Civil engineering
24
140 - Specific philosophical schools
21
665 - Industrial oils, fats, waxes & gases
19
630 - Agriculture & related technologies
16
340 - Law
15
541 - Physical chemistry
14
549 - Mineralogy
14
550 - Earth sciences
14
629 - Other branches of engineering
14
338 - Production
13
628 - Sanitary & municipal engineering
13
553 - Economic geology
10
720 - Architecture
10
800 - Literature & rhetoric
10
414 - Phonology & phonetics
9
526 - Mathematical geography
9
658 - General management
9
547 - Organic chemistry
6
577 - Ecology
5
627 - Hydraulic engineering
5
661 - Industrial chemicals
5
300 - Social sciences
4
344 - Labor, social, education & cultural law
4
370 - Education
4
560 - Paleontology; paleozoology
4
581 - Specific topics in natural history
4
657 - Accounting
4
003 - Systems
3
170 - Ethics
3
622 - Mining & related operations
3
more ...