Van Lint and Tonchev (1993, J. Combin. Theory Ser. A 62, 252 260) described a sufficient condition for the non-embeddability of a quasi-derived design into a symmetric balanced incomplete block design. In this paper, by using the notion of incomplete designs, this criterion is changed to find certain quasi-derived designs in some special cases. Many infinite series of non-embeddable quasi-deriv...
