Oscillatory and asymptotic properties of the solutions of a class of operator-differential equations. D. D. Bainov, M. D. Dimitrova, A. D. Myshkis (1994) Revista Matemática de la Universidad Complutense de Madrid
Oscillatory properties of a differential inclusion of order n > 1 and the asymptotic equivalence Marko Švec (1994) Czechoslovak Mathematical Journal
Oscillatory properties of the fourth order linear differential equation Jozef Rovder (1983) Mathematica Slovaca
Oб инвариантности характеристических показателей линейных систем при экспоненциально убывающих возмущениях Nikolai Alekseevich Izobov, O. P. Stepanovich (1990) Archivum Mathematicum