Some remarks on regular association schemes of order pqr

Let C be a non-thin regular association scheme of order pqr, where p, q and r are any prime numbers. ##Using the thin radical and thin residue, we give sufficient conditions for such association scheme to be schurian. ##Also, we show that C is isomorphic to the wreath product of two thin regular association schemes of order r and pq, if thin radical and thin residue are equal of order pq