1. E.A. BARBASHIN, N.N. KRASOVSKI, Sur la stabilité globale du mouvement (en russe), Dokl. Akad. Nauk. SSSR 86 (1952), 453–456.
2. L. CESARI, Asymptotic behavior and stability problems in ordinary differential equations, Springer-Verlag, Berlin, 1959.
3. R. CONTI, Sulla prolungabilità delle soluzioni di un sistema di equazioni differenziali ordinarie, Boll. Un. Mat. Ital. 11 (1956), 510–514.
4. C. CORDUNEANU, The application of differential inequalities to the theory of stability, An. Sti. Univ. “Al. I. Cuza” Iasi (1) 6 (1960), 47–58.
5. C. CORDUNEANU, Sur la stabilité partielle, Rev. Roumaine Math. Pures Appl. 9 (1964), 229–236.