§16§§The book presents integral formulations for partial differential equations, with the focus on spherical and plane integral operators. The integral relations are obtained for different elliptic and parabolic equations, and both direct and inverse mean value relations are studied. The derived integral equations are used to construct new numerical methods for solving relevant boundary value problems, both deterministic and stochastic based on probabilistic interpretation of the spherical and plane integral operators.§ §02§§Karl Sabelfeld and Irina Shalimova, Russian Academy of Sciences and Novosibirsk University, Novosibirsk, Russia.§
