
 PlanetMath: Beltrami differential equation (Site not responding. Last check: 20071022) 
  is a measurable function, then the partial differential equation 
  Crossreferences: imaginary parts, real, terms, complex conjugate, partial derivatives, conformal, conformal mapping, quasiconformal mapping, solution, domain, bound, uniform, partial differential equation, measurable function 
  This is version 5 of Beltrami differential equation, born on 20040210, modified 20040610. 
 planetmath.org /encyclopedia/BeltramiDifferentialEquation.html (131 words) 
