1. The Cauchy Problem for Linear Partial Differential Equations of Hyperbolic Type;Hadamard,1978
2. On the solution of ill-posed problems and the method of regularization;Tikhonov;Dokl. Akad. Nauk. SSSR,1963
3. Carleman’s Formulas in Complex Analysis;Aizenberg,1990
4. Partial Differential Equations;Bers,1966
5. Les Fonctions Quasi Analytiques;Carleman,1926