Nonlinear Wave Dynamics in Two Temperature Electron-Positron-Ion Plasma
  The hot electron-positron unmagnetized plasma with small fraction of cold electron-ion plasma is investigated. The modulational interactions of the electromagnetic waves and the electron-sound waves are studied. The possibility of soliton formation is investigated. 
N.L. Shatashvili, J.I. Javakhishvili and H. Kaya