Hadamard and conference matrices (Q1610680)

The authors present a recursive construction of relative difference sets using Golay complementary pairs and, for groups of order \(2n\), another construction to obtain skew (i.e. obtained by a not necessarily abelian group) symmetric conference matrices of size \(n\) and skew Hadamard matrices. So a relative \((n,2,n-1,(n-1)/2)\) difference set is obtained where \(n-1\) is not a prime power. Tiny interesting surveys to put treated questions in the right landscape are added.