Classification
520 - Astronomy & allied sciences
7
500 - Natural sciences & mathematics
5
620 - Engineering & allied operations
5
530 - Physics
4
507 - Education, research & related topics
3
509 - Historical, geographic & persons treatment
3
621 - Applied physics
3
808 - Rhetoric & collections of literature
3
004 - Data processing & computer science
2
300 - Social sciences
2
519 - Probabilities & applied mathematics
2
551 - Geology, hydrology & meteorology
2
610 - Medicine & health
2
001 - Knowledge
1
128 - Humankind
1
153 - Mental processes & intelligence
1
306 - Culture & institutions
1
330 - Economics
1
333 - Economics of land & energy
1
338 - Production
1
363 - Other social problems & services
1
370 - Education
1
501 - Philosophy & theory
1
510 - Mathematics
1
523 - Specific celestial bodies & phenomena
1
537 - Electricity & electronics
1
550 - Earth sciences
1
570 - Life sciences; biology
1
571 - Physiology & related subjects
1
601 - Philosophy & theory
1
613 - Personal health & safety
1
614 - Incidence & prevention of disease
1
629 - Other branches of engineering
1