Classification
520 - Astronomy & allied sciences
171
523 - Specific celestial bodies & phenomena
98
530 - Physics
14
500 - Natural sciences & mathematics
9
519 - Probabilities & applied mathematics
5
539 - Modern physics
5
001 - Knowledge
1
200 - Religion
1
300 - Social sciences
1
551 - Geology, hydrology & meteorology
1
572 - Biochemistry
1
621 - Applied physics
1
629 - Other branches of engineering
1