  In this paper, constructions of some double circulant self-dual codes by
generalized cyclotomic classes of order two are presented. This technique is
applied to [72, 36, 12] binary highest know self-dual codes to obtain self-dual
codes over GF(2) and [32, 16, 8] almost optimal self-dual codes over GF(4).
Based on the properties of generalized cyclotomy, some of these codes can be
proved to possess good minimum weights.
