This second edition also expands the area of applicability of boundary integral equations . The authors are outstanding and well known researchers in the mathematical foundations of numerical methods, mainly the boundary element methods, for solving various boundary integral equations. The multitude of their original results is the basis of this impressive volume which, however, requires a fairly high level of mathematical knowledge in order to be useful. (Calin Ioan Gheorghiu, zbMATH 1477.65007, 2022)