1. Les inéquations en Mécanique et en physique;Duvaut,1972
2. “Le système différentiel du/dt2 + ∂ϕ(u) ∋ f, avec conditions initiales,”;Schatzman;C. R. Acad. Sc. Paris,1977
3. “A Class of Nonlinear Differential Equations in Time,”;Schatzman;J. Nonlinear Anal. Theory, Meth. and Appl.,1978
4. “Study of the Motion of a String Vibrating Against an Obstacle,”;Amerio;Rend. di Matem.,1975
5. “Sull'urto parzialmente elastico o anelastico di una corda vibrante contro un ostacolo,”;Citrini;Rend. Accad. Naz. Lincei,1975