Regular Hadamard matrices constructed from Hadamard 2-designs and conference graphs

Suppose there exists a Hadamard 2-(m,m−12,m−34) design having skew incidence matrix. If there exists a conference graph on 2m−1 vertices, then there exists a regular Hadamard matrix of order 4m2. A conference graph on 2m+3 vertices yields a regular Hadamard matrix of order 4(m+1)2.