Classification
520 - Astronomy & allied sciences
274
530 - Physics
42
523 - Specific celestial bodies & phenomena
32
539 - Modern physics
11
500 - Natural sciences & mathematics
10
370 - Education
9
510 - Mathematics
7
629 - Other branches of engineering
7
306 - Culture & institutions
5
550 - Earth sciences
5
551 - Geology, hydrology & meteorology
5
621 - Applied physics
5
526 - Mathematical geography
4
301 - Sociology & anthropology
3
333 - Economics of land & energy
3
509 - Historical, geographic & persons treatment
3
519 - Probabilities & applied mathematics
3
541 - Physical chemistry
3
576 - Genetics & evolution
3
338 - Production
2
379 - Public policy issues in education
2
515 - Analysis
2
100 - Philosophy & psychology
1
170 - Ethics
1
305 - Social groups
1
320 - Political science
1
378 - Higher education
1
518 - Numerical analysis
1
535 - Light & infrared & ultraviolet phenomena
1
537 - Electricity & electronics
1