\begin{thebibliography}{1}

\bibitem{SEG-1986-S7.6}
Jean~Pierre Faye and Jean~P. Jeannot.
\newblock Prestack migration velocities from focusing depth analysis.
\newblock In {\em 56th Annual International Meeting, SEG, Expanded Abstracts},
  volume~86, page Session:S7.6. Soc. Expl. Geophys., 1986.

\bibitem{GEO57-12-16081622}
S.~MacKay and R.~Abma.
\newblock Imaging and velocity estimation with depth--focusing analysis.
\newblock {\em Geophysics}, 57(12):1608--1622, 1992.

\end{thebibliography}
