Myshkis, A.A., D.D. Bainov, y M.B. Dimitrova. «Oscillatory and Asymptotic Properties of the Solutions of a Class of Operator-Differential Equations». Revista Matemática Complutense 7, no. 2 (enero 1, 1994): 309. Accedido julio 30, 2026. https://revistas.ucm.es/index.php/REMA/article/view/REMA9494220309A.