1. Seneta, E., Regularly Varying Functions, Berlin-New York: Springer-Verlag, 1976. Translated under the title Pravil’no menyayushchiesya funktsii, Moscow: Nauka, 1985.
2. Kiguradze, I.T. and Chanturiya, T.A., Asimptoticheskie svoistva reshenii neavtonomnykh obyknovennykh differentsial’nykh uravnenii (Asymptotic Properties of Solutions of Nonautonomous Ordinary Differential Equations), Moscow, 1990.
3. Kostin, A.V., Asymptotics of the Regular Solutions of Nonlinear Ordinary Differential Equations, Differ. Uravn., 1987, vol. 23, no. 3, pp. 524–526.
4. Evtukhov, V.M., Asymptotic Properties ofMonotone Solutions of a Certain Class of nth-Order Nonlinear Differential Equations, Dokl. Rasshir. Sem. Inst. Prikl. Mat., 1988, vol. 3, no. 3, pp. 62–65.
5. Evtukhov, V.M., Asymptotic Representations of Monotone Solutions of an nth-Order Nonlinear Differential Equation of Emden-Fowler Type, Dokl. Akad. Nauk, 1992, vol. 234, no. 2, pp. 258–260.