1. L. Alpar, “Tauberian theorems for power series of two variables,” Studia Sci. Math. Hungar., 19, 165–176 (1984).
2. A. Baltrunas and E. Omey, “The rate of convergence for subexponential distributions,” Liet. Matem. Rink., 38, No. 1, 1–18 (1998).
3. A. Baltrunas and E. Omey, “The rate of convergence for subexponential distributions and densities,” Liet. Matem. Rink., 42, No. 1, 1–18 (2002).
4. B. Basrak, R. A. Davis, and T. Mikosch, “A characterization of multivariate regular variation,” Ann. Appl. Probab., 12, No. 3, 908–920 (2002).
5. N. H. Bingham, C. M. Goldie, and J. L. Teugels, Regular Variation, Cambridge Univ. Press, Cambridge (1987).