Product Constructions for Cyclic Block Designs. I. Steiner Quadruple Systems

Abstract Let CSQS(ν) denote a cyclic Steiner quadruple system of order ν. Various product constructions for CSQS(uν) are given. Amongst other results we show how to construct a CSQS(uν) (ν ≢ 0 (mod 4)) from a CSQS(u), a CSQS(2u) and a CSQS(ν).