Classification
551 - Geology, hydrology & meteorology
56
620 - Engineering & allied operations
30
900 - History & geography
26
600 - Technology
23
700 - The arts; fine & decorative arts
23
576 - Genetics & evolution
18
624 - Civil engineering
18
000 - Computer science, information & general works
16
363 - Other social problems & services
15
333 - Economics of land & energy
12
549 - Mineralogy
8
414 - Phonology & phonetics
7
530 - Physics
7
540 - Chemistry & allied sciences
6
550 - Earth sciences
6
340 - Law
5
380 - Commerce, communications & transportation
5
001 - Knowledge
4
300 - Social sciences
4
621 - Applied physics
4
910 - Geography & travel
3
005 - Computer programming, programs & data
2
006 - Special computer methods
2
301 - Sociology & anthropology
2
553 - Economic geology
2
580 - Plants (Botany)
2
610 - Medicine & health
2
628 - Sanitary & municipal engineering
2
650 - Management & auxiliary services
2
770 - Photography, photographs & computer art
2
800 - Literature & rhetoric
2
304 - Factors affecting social behavior
1
306 - Culture & institutions
1
320 - Political science
1
378 - Higher education
1
500 - Natural sciences & mathematics
1
526 - Mathematical geography
1
541 - Physical chemistry
1
569 - Fossil mammals
1
570 - Life sciences; biology
1
577 - Ecology
1
625 - Engineering of railroads & roads
1
630 - Agriculture & related technologies
1
631 - Techniques, equipment & materials
1
660 - Chemical engineering
1
670 - Manufacturing
1
720 - Architecture
1
917 - Geography of & travel in North America
1
930 - History of ancient world to ca. 499
1