“…Nor can we do justice to the large body of recent work on (Cauchy) singular integral equations in the plane (see, for example, Prossdorf andSilbermann (1977, 1991), Prossdorf (1989)). Mixed boundary value problems will be ignored (see Wendland et al (1979), Lamp et al (1984), Stephan and Wendland (1985), McLean (1990)). And we will have nothing to say about another topic currently attracting considerable interest, namely nonlinear aspects of BIE (see Ruotsalainen and Wendland (1988), Ruotsalainen and Saranen (1989), Atkinson and Chandler (1990), Eggermont and Saranen (1990), Ruotsalainen (1992); and, in connection with coupling of BIEs and PDEs, Gatica and Hsiao (1989)).…”