Hakobyan G. Margarjan V., “Behavior of the Higher Order Derivatives of Solutions of a Class of Nonhypoelliptic Equations in the Infinite Cylinder”, Proceedings of the Second ISAAC Congress, Vols 1 and 2, International Society for Analysis, Applications and Computation, 7, ed. Begehr H. Gilbert R. Kajiwara J., Springer, 2000, 1143–1147
