$N=1$ supersymmetry and the three loop gauge beta function
  We calculate the three loop gauge $\beta$-function for an abelian $N=1$ supersymmetric gauge theory, using DRED. We construct a coupling constant redefinition that relates the result to the corresponding term in the NSVZ $\beta$-function, and by generalising this redefinition to the non-abelian case we derive the DRED three loop gauge $\beta$-function for the non-abelian case. 
I. Jack, D.R.T. Jones and C.G. North