@inbook{marston:1992:gco,
    author = {Marston, P. L.},
     title = {Geometrical and Catastrophe Optics Methods in Scattering},
 booktitle = {Physical Acoustics},
    editor = {Pierce, A. D. and Thurston, R. N.},
    volume = {21},
      year = {1992},
     pages = {1–234},
 publisher = {Academic Press},
   address = {New York}}