1. Stability of Nonlinear Control Systems;Lefschetz,1965
2. The qualitative behavior of a nonlinear Volterra equation;Levin,1965
3. Some problems in nonlinear Volterra integral equations;Nohel;Bull. Am. Math. Soc.,1962
4. A general property of boundedness for the power of some stable and unstable nuclear reactors;Smets;Nukleonik,1960
5. Transitoires bornés pour certains systèmes a boucle unique contenant un élément non-linéaire;Smets;Automatisme,1965