1. H.F. Bueckner, Field singularities and related integral representations, in Methods of analysis and solutions of crack problems, edited by George C. Sih, Noordhoff International Publishing, Leiden (1973).
2. V. V. Panasyuk, Limiting equilibrium of brittle solids with fractures, translation from Russian; distributed in 1971 by Management Information Services, P.O. Box 5129, Detroit, Michigan 48236.
3. N.I. Muskhelishvili, (1) Some basic problems of the mathematical theory of elasticity, (translated from Russian), third edition, P. Noordhoff, N.V., Groningen, Holland (1953); fifth edition (Russian), Moscow (1966). (2) Singular integral equations, (translated from Russian), 2nd edition, P. Noordhoff, N.V., Groningen, Holland (1953).