Perera, A.A.I.2013-06-242013-06-242009Ceylon Journal of Science (Physical Sciences), 15:p.17-25https://dl.nsf.gov.lk/handle/1/9810MathematicsContemporary design theoryCombinatorial mathematicsGraphsDesignsDifference setsQuadratic residuesEquivalence of square designs, difference sets and complete graphsA