There are finitely many Q-polynomial association schemes with given first multiplicity at least three. - William J. Martin; Jason S. Williford (Eur. J. Comb., 2009)

On few-class Q-polynomial association schemes: feasible parameters and nonexistence results. - Alexander L. Gavrilyuk; Janos Vidali; Jason S. Williford (Ars Math. Contemp., 2021)