Dd. Bainov et Mb. Dimitrova, PROPERTIES OF THE OSCILLATING AND NONOSCILLATING SOLUTIONS OF OPERATOR-DIFFERENTIAL EQUATIONS, Indian Journal of Pure and Applied Mathematics, 25(7), 1994, pp. 699-710
In the present paper the properties of the oscillating solutions of a
class of operator-differential equations are investigated. Effective s
ufficient conditions for nonoscillation of all solutions of the operat
or-differential equations considered are found.