Renormalization--Group Solutions for Yukawa Potential
  The self--similar renormalization group is used to obtain expressions for the spectrum of the Hamiltonian with the Yukawa potential. The critical screening parameter above which there are no bound states is also obtained by this method. The approach presented illustrates that one can achieve good accuracy without involving extensive numerical calculations, but invoking instead the renormalization--group techniques. 
V. I. Yukalov, E. P. Yukalova, and F. A. Oliveira