[[1] M. Abramowitz, I. Stegun, Handbook of Mathematical Functions with Formulas, Graphs, and Mathematical Tables.National Bureau of Standards Applied Mathematics Series, no.55, Washington,DC: US Government Printing Office 1964.10.1115/1.3625776]Search in Google Scholar
[[2] T. R. Blows, G. N. Lloyd, The number of small-amplitude limit cycles of Linard equations. Math. Proc. Camb. Phil. Soc. 1984;95:359-366.10.1017/S0305004100061636]Search in Google Scholar
[[3] A. Boulfoul, A. Makhlouf and M. Mellahi, On the limit cycles for a class of generalized Kukles differential systems, Journal of Applied Analysis and Computation 2019; 9:864-883.10.11948/2156-907X.20180083]Search in Google Scholar
[[4] A. Buica, J. Llibre, Averaging methods for finding periodic orbits via Brouwer degree, Bull. Sci. Math. 2004;128:7-22.10.1016/j.bulsci.2003.09.002]Search in Google Scholar
[[5] C. J. Christopher, S. Lynch, Limit cycles in highly non-linear differential equations, Journal of Sound and Vibration. 1999;224:505-517.10.1006/jsvi.1999.2199]Search in Google Scholar
[[6] W. A. Coppel, Some quadratic systems with at most one limit cycles. Dynamics reported, Vol. 2. New York: Wiley; 1998.]Search in Google Scholar
[[7] P. De Maesschalck, F. Dumortier, Classical Linard equations of degree n ≥ 6 can have [(n − 1)/2] limit cycles. J Differ Equ 2011;250:2162-76.10.1016/j.jde.2010.12.003]Search in Google Scholar
[[8] F. Dumortier, C. Li, On the uniqueness of limit cycles surrounding one or more singularities for Linard equations. Nonlinearity 1996;9:1489-500.10.1088/0951-7715/9/6/006]Search in Google Scholar
[[9] F. Dumortier, C. Li, Quadratic Linard equations with quadratic damping. J Differ Equ 1997; 139:41-59.10.1006/jdeq.1997.3291]Search in Google Scholar
[[10] F. Dumortier, D. Panazzolo, R. Roussarie, More limit cycles than expected in Linard systems. Proc Am Math Soc 2007;135:1895-904.10.1090/S0002-9939-07-08688-1]Search in Google Scholar
[[11] F. Dumortier, C. Rousseau, Cubic Linard equations with linear dapimg. Nonlinearity 1990; 3:1015-1039.10.1088/0951-7715/3/4/004]Search in Google Scholar
[[12] B. Garca, J. Llibre, J. S. Prez del Ro, Limit cycles of generalized Linard polynomial differential systems via averaging theory. Chaos, Solitons Fractals 2014;62-63:1-9.10.1016/j.chaos.2014.02.008]Search in Google Scholar
[[13] A. Gasull, J. Torregrosa, Samll-amplitude limit cycles in Linard systems via multiplicity. J Differ Equ 1998;159:1015-1039.10.1006/jdeq.1999.3649]Search in Google Scholar
[[14] D. Hilbert, Mathematische probleme, em lecture in: secondInternat. Cong. Math, Paris, 1900, Nachr. Ges. Wiss. Gttingen. Math. Phys. Ki 5 (1900), 253-297; English Transl: Bull. Amer. Math. Soc. 1902;8:437-479.]Search in Google Scholar
[[15] C. Li, J. Llibre, Uniqueness of limit cycles for Linard differential equations of degree four. J Differ Equ 2012;252:3142-62.10.1016/j.jde.2011.11.002]Search in Google Scholar
[[16] A. Linard, tude des oscillations entrenues. Revue gnrale de l'lectricit 1928;23:946-954.]Search in Google Scholar
[[17] A. Lins, W. de Melo, C. C. Pugh, On Linard's equation, Lecture notes in Math Nonlinear 597, Springer, 1977;pp:335-357.10.1007/BFb0085364]Search in Google Scholar
[[18] J. Llibre, A. C. Mereu, M.A Teixeira, Limit cycles of the generalized polynomial Linard differential equations. Math Proc Camb Phil Soc 2010;148:363-383.10.1017/S0305004109990193]Search in Google Scholar
[[19] J. Llibre, C. Valls, Limit cycles for a generalization of Linard polynomial differential systems. Chaos Solitons Fractals 2013;46:65-74.10.1016/j.chaos.2012.11.010]Search in Google Scholar
[[20] J. Llibre, C. Valls, On the number of limit cycles for a generalization of Linard polynomial differential systems. Int J Bifurcation Chaos 2013;23 1350048-16.10.1142/S021812741350048X]Search in Google Scholar
[[21] J. Llibre, C. Valls, On the number of limit cycles of a class of polynomial differential systems. Proc A R Soc 2012;468:2347-2360.10.1098/rspa.2011.0741]Search in Google Scholar
[[22] G. N. Lloyd, Limit cycles of polynomial systems-some recent developments. London Math. Soc. Lecture note Ser. 127, Cambridge University Press 1988;PP:192-234.10.1017/CBO9780511600777.007]Search in Google Scholar
[[23] N. G. Lloyd, S. Lynch, Small-amplitude Limit cycles of certain Linard systems, Proc. Royal Soc. Proc R Soc Lond Ser A 1988;418:199-208.10.1098/rspa.1988.0079]Search in Google Scholar
[[24] S. Lynch, Limit cycles of generalized Linard equations. Appl. Math. Lett. 1995;8:15-17.10.1016/0893-9659(95)00078-5]Search in Google Scholar
[[25] N. Mellahi, A. Boulfoul and A. Makhlouf, Maximum number of limit cycles for generalized Kukles polynomial differential systems, Diff. Equ. Dyn. Syst 2019; 27(4):493-514.10.1007/s12591-016-0300-3]Search in Google Scholar
[[26] G. S. Rychkov, The maximum number of limit cycle of the systemx˙ = y − a1x3− a2x5, y˙ = −x is two. Differ Uravn 1975;11:380-391.]Search in Google Scholar
[[27] J. A. Sanders, F. Verhust, Averaging Methods in Nonlinear Dynamical Systems, Applied Mathematical Sciences.59 Springer-Verlag, New York; 1985.10.1007/978-1-4757-4575-7]Search in Google Scholar
[[28] S. Smale, Mathematical problems for the next century. Math. Intelligencer 1998;20:7-15.10.1007/BF03025291]Search in Google Scholar
[[29] F. Verhulst, Nonlinear Differential Equations and Dynamical Systems, em Berlin: Springer-Verlag, Second Edition; 1991.10.1007/978-3-642-97149-5]Search in Google Scholar
[[30] P. Yu, M. Han, Limit cycles in generalized Linard systems. Chaos Solitons Fract 2006;30:1048-1068.10.1016/j.chaos.2005.09.008]Search in Google Scholar