References
[1] Durgapal, M.C. and Gehlot, G.L. (1968) Exact Internal Solutions for Dense Massive Stars. Physical Review, 172, 1308-1309.
http://dx.doi.org/10.1103/PhysRev.172.1308
[2] Chandrasekhar, S. (1958) An Introduction to the Study of Stellar Structure. Dover Publications Inc., Mineola.