[1] Ascoli G.: Sul comportamento asintotico degli integrali delle equazioni differenziali del 2° ordine. Atti della R. Accad. Naz. dei Lincei, Rendiconti, ser. 6, vol. XXII (1935), 234-243.
[2] Bellman R.:
Boundedness of the solutions of second order linear differential equations. Duke Math. Journal 22 (1955), 511-513.
MR 0075376 |
Zbl 0066.33403
[3] Pinney E.: The non linear differential equation. Proceedings of the Amer. Math. Soc, 1 (1950), p. 681.
[6] Zlámal M.:
Über asymptotische Eigenschaften der Lösungen der linearen Differentialgleichung zweiter Ordnung. Чех. мат. Журнал, м. 6 (81) 1956, 75-93.
MR 0080215