On a Generalized Oscillator System: Interbasis Expansions
  This article deals with a nonrelativistic quantum mechanical study of a dynamical system which generalizes the isotropic harmonic oscillator system in three dimensions. The problem of interbasis expansions of the wavefunctions is completely solved. A connection between the generalized oscillator system (projected on the z-line) and the Morse system (in one dimension) is discussed. 
M. Kibler, L.G. Mardoyan and G.S. Pogosyan