Effective sufficient conditions for the uniform oscillation of a linear differential equation

A Method for Studying Oscillations of Nonlinear Differential Equations. Applications to Some Equations in Biology and Economics

“…Remark 2 Equations (4) admit oscillatory solutions, see [3]. Proof Note that under the conditions of Theorem 1 the solutions y(t) can have only zeros, say t * ν , ν = 1, 2, ..., N (t 1 , t 2 , y), that satisfy y (t * ν ) = 0.…”