2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/147902We present the estimates of the order $O(α^{4}_{s})$ QCD corrections to $R(s)$, $R_τ$ and to the deep-inelastic scattering sum rules, namely to the non-polarized and polarized Bjorken sum rules and to the Gross-Llewellyn Smith sum rule. The estimates are obtained in the $\overline{MS}$-scheme using the principle of minimal sensitivity and the effective charges approach.CERN-TH.7190/94, to appear in Proc. of the Workshop "QCD at LEP: Determinations of $α_s$ from Inclusive Observables", Aachen, Germany 11 April, LATEX, 11 pages; extended version submitted for publication. Some misprints in the previous version corrected, thanks to F. Le Diberder for pointing them, PMS results in Tables 1-4 are affected. Changes do not affect main resultsHigh Energy Physics - Phenomenologytext