“…Looking at the minimal degree for a non-trivial permutation representation of a classical group we obtain that in most cases the representation must be trivial and from this a contradiction follows by the existence of too large planar p-groups. Since the Cooperstein's paper [6] on the minimal degree for a non-trivial permutation representation of a classical group contains some inaccuracies, the Cooperstein's results are intended to be corrected comparing with [26,34,35].…”