1.
LLIBRE, Jaume and DA SILVA, Maurício Fronza. Global phase portraits of Kukles differential systems with homogenous polynomial nonlinearities of degree 5 having a center. Topological Methods in Nonlinear Analysis. Online. 7 August 2016. Vol. 48, no. 1, pp. 257 - 282. [Accessed 22 July 2024].