Gray soliton solution in the extended nonlinear Schrodinger equation
  In the framework of extended nonlinear Schrodinger equation (ENSE) the classification of self-similar solutions by the relation between the amplitude and phase is performed. New solutions of ENSE - ``gray soliton'' and ``gray soliton chain'' are presented. The properties of these solutions and the possibility for using theirs in physical applications are discussed. 
M. A. Borich, V. V. Smagin and A. P. Tankeyev