Approximate Solution of the effective mass Klein-Gordon Equation for the   Hulthen Potential with any Angular Momentum
  The radial part of the effective mass Klein-Gordon equation for the Hulthen potential is solved by making an approximation to the centrifugal potential. The Nikiforov-Uvarov method is used in the calculations. Energy spectra and the corresponding eigenfunctions are computed. Results are also given for the case of constant mass. 
Altug Arda and Ramazan Sever