“…They give the GP-graphs Γ(q ℓ + 1, q m ), with q = p, considered in [20] for q a power of p. Notice that the graphs Γ(3, 2 2t ) with t ≥ 2 and Γ(4, 3 2t ) with t ≥ 1 belong to both families given in (i) and (ii). For instance, Γ (3,16), Γ(3, 64), and Γ(4, 81) are semiprimitive GP-graphs.…”