  The propagation characteristics and interactions between the dust acoustic
(DA) one and multi solitons in an unmagnetized dusty plasmas composing
negatively charged mobile dust, Boltzmann distributed electrons, nonextensive
distributed cold and nonthermal distributed hot ions are studied. The well
known extended Poincar Lighthill Kuo (PLK) method is employed to derive the two
sided Korteweg de Vries (KdV) equations. The solutions of KdV equations are
constructed using the Hirota method both for one and multi solitons. The phase
shifts are determined for the interaction of one, two and three DA solitons.
The effects of plasma parameters on the head on collision of DA one as well as
multi solitons and their corresponding phase shifts are investigated.
