[en] Spectroscopic factors derived from (d,n), (tau,d) and (d,p) reactions on the target nuclei ²⁶Mg, ²⁹Si, ³⁰Si and ³¹P are compared. For the Tsub(>) states, the spectroscopic factors deduced by means of the (tau,d) reactions are generally very close to those determined in (d,n) experiments with a mean ratio Rsub(s)(ave) = Ssub(tau,d)/Ssub(d,n) = 1.04 +- 0.03. But important differences between these spectroscopic factors are found for transitions leading to Tsub(>) states where Rsub(S) = 1.79 +- 0.24. Anomalies exist also between Ssub(d,n) for Tsub(>) states and Ssub(d,p)) for the parent states, for which a mean ratio Ssub(d,p)/Ssub(d,n) = 1.75 +- 0.11 was found. (Auth.)