Solutions of the Modified Chiral Model in (2+1) Dimensions
  This paper deals with classical solutions of the modified chiral model on $R^{2+1}$. Such solutions are shown to correspond to products of various factor which we call time-dependent unitons. Then the problem of solving the system of second-order partial differential equations for the chiral field is reduced to solving a sequence of systems of first-order partial differential equations for the unitons. 
Theodora Ioannidou and Wojtek Zakrzewski