1. Nonlinear Semigroups and Differential Equations in Banach Spaces;Barbu,1976
2. Nonlinear Volterra integro-differential equations in Hilbert spaces;Barbu,1976
3. V. Barbu, Existence for Nonlinear Volterra Equations in Hilbert Spaces, to appear.
4. Nonlinear boundary-value problems for a class of hyporbalic systems;Barbu;Revue Roumaine Math. Pures Appl.,1977
5. Opérateurs Maximaux Monotones et Semigroupes de Contractions dans les espaces de Hilbert;Brezis,1973