Sachin Kumar and  Y. K. Gupta and  J. R. Sharma,  Some Static Isotropic Perfect Fluid Spheres in General Relativity.   journal   = {International Journal of Mathematical and Computational Sciences}, [online]. World Academy of Science, Engineering and Technology.
    February 2010, vol. 38(2). 259 - 263
    [viewed 24 April 2024]. Available from: https://publications.waset.org/pdf/4453.