chandrashekhar limit for relativistic fermion gas

hi fellas, I have been working on Chandrashekhar limit, and I found a mass-radius relationship for the nonrelativistic fermi gases using this formula and i got the graph of this



R=((18pi)^(2/3))/10 *H^2/(GmM^(1/3) ) (0.5/n)^(5/3)



where H=(6.63*10^-34)/2pi

G=6.67*10^-11

m=9.11*10^-31

n=1.67*10^-27

M is the independent variable



but what changes should I make if i want to plot a mass-radius relationship for relativistic fermi gases? actually can you suggest me a reading for differentiating between relativistic and non relativistic fermi gases?

thanks