Romanovskii R. K., Bel’gart L. V.
          Exponential dichotomy of  linear systems with almost periodic matrices
        Using the Lyapunov  direct method, we establish a condition of exponential dichotomy for the class  of dynamical systems under weaker assumptions as compared to the case of an  arbitrary continuous matrix on the derivative of the Lyapunov function along  the trajectories. By way of application, we obtain a sufficient condition for  the dichotomy of a second order almost periodic vector equation in terms of  coefficients.