The Construction of Some Important Classes of Generalized Coherent   states: The Nonlinear Coherent States Method
  Considering some important classes of generalized coherent states known in literature, we demonstrated that all of them can be created via conventional fashion, i.e. the "lowering operator eigen-state" and the "displacement operator" techniques using the {\it "nonlinear coherent states"} approach. As a result we obtained a {\it "unified method"} to construct a large class of coherent states which already have been introduced by different prescriptions. 
R. Roknizadeh, M. K. Tavassoly