Dynamics of quasiconformal fields
  A uniqueness theorem is established for autonomous systems of ODEs, $\dot{x}=f(x)$, where $f$ is a Sobolev vector field with additional geometric structure, such as delta-monoticity or reduced quasiconformality. Specifically, through every non-critical point of $f$ there passes a unique integral curve. 
Tadeusz Iwaniec, Leonid V. Kovalev, Jani Onninen