An examination of approaches to easy-to-understand but difficult-to-solve mathematical problems, this classic text begins with a discussion of Dirichlet's principle and the boundary value problem of potential theory, then proceeds to examinations of conformal mapping on parallel-slit domains and Plateau's problem. Also explores minimal surfaces with free boundaries and unstable minimal surfaces. 1950 edition. Republication of the New York, 1950 edition.
Here's a sample of other books in this Dover category
Conformal Mapping: Methods and Applications by Roland Schinzinger, Patricio A. A. Laura This volume introduces the basic mathematical tools behind conformal mapping, describes advances in technique, and illustrates a broad range of applications. 1991 edition. Includes 247 figures and 38 tables.
A Survey of Minimal Surfaces by Robert Osserman Explores parametric and nonparametric surfaces, surfaces that minimize area, isothermal parameters on surfaces, Bernstein's theorem, more. Revised edition explores minimal surfaces in relativity and topology, updated work on Plateau's problem, more. 1969 edition.
Lectures on Classical Differential Geometry: Second Edition by Dirk J. Struik Excellent brief introduction presents fundamental theory of curves and surfaces and applies them to a number of examples. Topics include curves, theory of surfaces, fundamental equations, envelopes, more. Many problems and solutions. Bibliography.