1. Non-Archimedean Analogues of Orthogonal and Symmetric Operators and p-adic Quantization

   • Sergio Albeverio
   • Jose Manuel Bayod
   • Andrew Khrennikov

   OriginalPaper Pages: 205 - 237

2. The Inverse Problem of the Calculus of Variations: Separable Systems

   • M. Crampin
   • G. E. Prince
   • G. Thompson

   OriginalPaper Pages: 239 - 254

3. Lightlike Hypersurfaces on Manifolds Endowed with a Conformal Structure of Lorentzian Signature

   • Maks A. Akivis
   • Vladislav V. Goldberg

   OriginalPaper Pages: 255 - 285

4. On the Dido Problem and Plane Isoperimetric Problems

   • Andrei A. Agrachev
   • Jean-Paul A. Gauthier

   OriginalPaper Pages: 287 - 338

5. Contents to Volume 57

   OriginalPaper Pages: 339 - 340