1. Positive solutions of elliptic partial differential equations;Saylor;J. Math. Anal. Appl.,1968
2. Numerical elliptic continuation;Saylor;SIAM J. Numer. Anal.,1967
3. Approximate continuation of harmonic and parabolic functions;Douglas,1966
4. A numerical method for analytic continuation;Douglas,1960
5. Mathematical programming and integral equations;Douglas,1960