(:notitlegroup:) 

   @article{jasa89,
    title     = {Self-Consistent Perturbation Approach to Rough Surface Scattering in
                Stratified Elastic Media},
    author    = {Wiliam A. Kuperman and Henrik Schmidt},
    journal   = {Journal Acoustical Society of America},
    pages     = {1511--1522},
    volume    = {86},
    year      = {1989}}