J. Llibre, R. D. S. Oliveira, C. A. B. Rodrigues.
Quadratic systems with an invariant algebraic curve of degree 3 and a Darboux invariant.
Electron. J. Differential Equations, 2021(69), 1-52. 2021.
PreprintAbstractPreprint at DDDUAB

J. Llibre, R. D. S. Oliveira, Y. Zhao.
On the birth and death of algebraic limit cycles in quadratic differential systems.
European J. Appl. Math., 32, 317-336. 2021. [DOI]
PreprintAbstractPreprint at DDDUAB

J. Llibre, D. Pasca, C. Valls.
The circular restricted 4-body problem with three equal primaries in the collinear central configuration of the 3-body problem.
Celestial Mech. Dynam. Astronom., 133(53), 1-13. 2021. [DOI]
PreprintAbstractPreprint at DDDUAB

J. Llibre, C. Pessoa, J. D. Ribeiro.
Rational first integrals of the Liénard equations: The solution to the Poincaré problem for the Liénard equations.
An. Acad. Brasil. Ci., 93(4), 1-7. 2021. [DOI]
PreprintAbstractPreprint at DDDUAB

J. Llibre, R. O. Ramírez, V. Ramírez.
Complete integrability of vector fields in $R^N$.
J. Geom. Phys., 168, 104308:1-25. 2021. [DOI]
PreprintAbstractPreprint at DDDUAB

J. Llibre, R. O. Ramírez, V. Ramírez.
The center problem for the class of $\lambda$-$\Omega$ differential systems.
Rend. Circ. Mat. Palermo (2), 70, 1483-1499. 2021. [DOI]
PreprintAbstractPreprint at DDDUAB

J. Llibre, A. Sá.
Minimal set of periods for continuous self-maps of the eight space.
Fixed Point Theory Algorithms Sci. Eng., 2021(3), 1-26. 2021. [DOI]
PreprintAbstractPreprint at DDDUAB

J. Llibre, T. Saeed, E. E. Zotos.
Periodic orbits and equilibria for a seventh-order generalized Hénon-Heiles Hamiltonian system.
J. Geom. Phys., 167, 104290:1-12. 2021. [DOI]
PreprintAbstractPreprint at DDDUAB

J. Llibre, T. Salhi.
On a class of polynomial differential systems of degree 4: phase portraits and limit cycles.
Topol. Methods Nonlinear Anal., 57(1), 441-463. 2021. [DOI]
PreprintAbstractPreprint at DDDUAB

J. Llibre, V. F. Sirvent.
Entropy and periods for continuous graph maps.
Comput. Appl. Math., 40, 300:1-11. 2021. [DOI]
PreprintAbstractPreprint at DDDUAB

J. Llibre, V. F. Sirvent.
Periodic structure of the transversal maps on surfaces.
J. Fixed Point Theory Appl., 23(74), 1-13. 2021. [DOI]
PreprintAbstractPreprint at DDDUAB

J. Llibre, Y. Tian.
Dynamics of the FitzHugh-Nagumo system having invariant algebraic surfaces.
Z. Angew. Math. Phys., 72, 15. 2021. [DOI]
PreprintAbstractPreprint at DDDUAB

J. Llibre, Y. Tian.
The zero-Hopf bifurcations of a four-dimensional hyperchaotic system.
J. Math. Phys., 62(052703), 1-9. 2021. [DOI]
PreprintAbstractPreprint at DDDUAB

J. Llibre, Y. Tian.
Generalized analytic integrability of a class of polynomial differential systems in $C^2$.
Acta Appl. Math., 173(1), 1-17. 2021. [DOI]
PreprintAbstractPreprint at DDDUAB

J. Llibre, Y. Tian.
A survey on the Kovalevskaya exponents and their applications.
J. Math. Anal. Appl., 504(2), 125576. 2021. [DOI]
PreprintAbstractPreprint at DDDUAB

J. Llibre, C. Valls.
Limit cycles of planar piecewise differential systems with linear Hamiltonian saddles.
Symmetry (Basel), 13, 1128:1-10. 2021. [DOI]
PreprintAbstractPreprint at DDDUAB

J. Llibre, C. Valls.
Weierstrass integrability of complex differential equations.
Acta Math. Sinica (N.S.), 37(10), 1497-1506. 2021. [DOI]
PreprintAbstractPreprint at DDDUAB

J. Llibre, C. Valls.
A sufficient condition for the real Jacobian conjecture in $R^2$.
Nonlinear Anal. Real World Appl., 60, 103298:1-10. 2021. [DOI]
PreprintAbstractPreprint at DDDUAB

J. Llibre, C. Valls.
Configurations of the topological indices of the planar polynomial differential systems of degree (2,m).
Results Math., 76, 21. 2021. [DOI]
PreprintAbstractPreprint at DDDUAB

J. Llibre, C. Valls.
Rational limit cycles on Abel equations.
Commun. Pure Appl. Anal., 20(3), . 2021. [DOI]
PreprintAbstractPreprint at DDDUAB