Potential relations for nonrelativistic and relativistic two-body   Schroedinger equations
  Relations between nonrelativistic and relativistic two-body equations, also allowing for different masses, are studied and explicit expressions are given. One example is the Blankenbeclar Sugar equation. The corresponding expressions for the boosted two-body potentials are provided. 
H. Kamada (Kyushu Ins. of Tech.), W. Gloeckle (Ruhr-U. Bochum)