[1]
A. H. Petrosyan and L. G. Khachatryan, “ABOUT EXPANSION BY EIGEN FUNCTIONS SELF-ADJOINT DIFFERENTIAL OPERATOR’S WITH COEFFICIENTS HAVING PRECISE BEHAVIOUR IN INFINITY”, Proc. YSU A: Phys. Math. Sci., vol. 38, no. 1 (203), pp. 22–27, Dec. 2003.