Renormalization scheme and higher loop stability in hadronic τ decay within analytic perturbation theory K.A. Milton, I.L. Solovtsov, O.P. Solovtsova and V.I. YasnovEur. Phys. J. C, 14 3 (2000) 495-501DOI: https://doi.org/epjc/v14/p495(epjc0370)