1. A. P. CALDERON, Cauchy integrals on Lipschitz curves and related operators, Proc. Nat. Acad. Sci. USA, 74 (1977), 1324?1327
2. Math. monographs;I. Gohberg,1974
3. I. GOHBERG and M. G. KREIN, The basic propositions on defect numbers, root numbers and indices of linear operators, Uspehi Mat. Nauk, 12 (1957), 43?118; (English transl., Amer. Math. Soc. Transl., 13 (1960), 185?264
4. I. GOHBERG and N. Ya. KRUPNIK, Introduction to the theory of one-dimensional singular integral operators, German transl., Berkhauser Verlag, Basel, 1979
5. G. HEINIG, On the inversion and on the spectrum of Weiner-Hopf matrix operators, Math. USSR Sbornik, 20 (1973), 267?281