This Monograph contains a collection of problems arising in partial differential equations investigated by means of complex analysis approached in elementary ways.1. Elliptic systems in the plane 2. Higher-dimensional linear elliptic systems 3. Degenerate elliptic problems 4. Nonstationary systems 5. First-order overdetermined systems 6. The statement of well-posed problems for degenerate systems of partial differential equationsThis book contains a collection of problems, including boundary-value problems for elliptic systems and initial-boundary-value problems for hyperbolic systems, arising in partial differential equations investigated by means of complex analysis approached in elementary ways.US? Longman Group UK Limited 1992