The authors investigate oscillatory properties of solutions to the th-order linear differential equation
where is a locally integrable function of constant sign and is a continuous nondecreasing function such that as . Equation (1) is studied as an ordinary differential equation () as well as a functional-differential equation in both the delayed case () and the advanced case ().
In a series of statements some sufficient conditions for equation (1) to have property or property are established. Moreover, comparisons with known results are given.