Evtukhov, V.M.: Asymptotic representations of solutions of nonautonomous ordinary differential equations. Doctoral (Phys.-Math.) Dissertation, Kiev (1998).
 Evtukhov, V.M., Elshour, Mousa Jaber Abu: Asymptotic behaviour of solutions of the nonautonomous ordinary differential $n$-th order equations. Nonlinear Oscillations 19 (1) (2016), 22–31.
 Evtukhov, V.M., Samoilenko, A.M.: Conditions for the existence of solutions of real nonautonomous systems of quasilinear differential equations vanishing at a singular point
. Ukrainian Math. J. 60 (1) (2010), 56–86. DOI 10.1007/s11253-010-0333-7
| MR 2888579
| Zbl 1224.35033
 Evtukhov, V.M., Samoilenko, A.M.: Asymptotic representations of solutions of nonautonomous ordinary differential equations with regularly varying nonlinearities
. Differ. Uravn. 47 (5) (2011), 628–650. MR 2918280
| Zbl 1242.34092
 Kiguradze, I.T., Chanturia, T.A.: Asymptotic properties of solutions of nonautonomous ordinary differential equations
. Kluwer Academic Publishers Group Dordrecht, 1993. MR 1220223
| Zbl 0782.34002
 Seneta, E.: Regularly Varying Functions
. Berlin Springer-Verlag, 1976, Translated under the title Pravil'no menyayushchiesya funktsii, Moscow Nauka, 1985. MR 0815924
| Zbl 0324.26002