(en) Martin Harwit, In Search of the True Universe : The Tools, Shaping, and Cost of Cosmological Thought, Cambridge University Press, , 456 p. (lire en ligne), p. 38
(en) Jennifer Johnson, Extreme Stars : White Dwarfs and Neutron Stars : Lecture notes, Astronomy 162, Columbus, Ohio, (E.-U.), Ohio State University (lire en ligne)