1. Wilson, R. N., Reviews in Modern Astronomy 7, 1(1994)
2. Astronomische Mittheilun;Schwarzschild;Koeniglichen Sternwarte zu Goettingen,1905
3. Annalen der Physik
4. Wide field aplanatic two-mirror telescopes for ground-based γ-ray astronomy
5. The 100th birthday of the conic constant and Schwarzschild’s revolutionary papers in optics;Rakich,2005