J. Llibre, C. Pessoa.
Phase portraits for quadratic homogeneous polynomial vector fields on $ S^2$.
Rend. Circ. Mat. Palermo (2), 58, 361-406. 2009. [DOI]
Abstract

J. Llibre, C. Pessoa.
On the centers of the weight-homogeneous polynomial vector fields on the plane.
J. Math. Anal. Appl., 359(2), 722-730. 2009. [DOI]
Abstract

J. Llibre, V. Pilyugina.
Number of invariant straight lines for homogeneous polynomial vector fields of arbitrary degree and dimension.
J. Dyn. Diff. Equat., 21(3), 487–499. 2009. [DOI]
Abstract

J. Llibre, L. A. Roberto.
Pseudo periodic orbits of the planar collision restricted 3-body problem in rotating coordinates.
Nonlinear Anal., 71(1-2), 58-65. 2009. [DOI]
Abstract

J. Llibre, L. A. Roberto.
New doubly-symmetric families of comet-like periodic orbits in the spatial restricted (N+1)-body problem.
Celestial Mech. Dynam. Astronom., 104, 307-318. 2009. [DOI]
Abstract

J. Llibre, R. Saghin.
Results and open questions on some of the invariants measuring the dynamical complexity of a map.
Fund. Math., 206, 307-327. 2009. [DOI]
Abstract

J. Llibre, N. Sellami, A. Makhlouf.
Limit cycles for a class of fourth-order differential equations.
Applicable Analysis, 88, 1617-1630. 2009. [DOI]
Abstract

J. Llibre, V. F. Sirvent.
Minimal sets of periods for Morse-Smale diffeomorphisms on orientable compact surfaces.
Houston J. Math., 35(3), 835-855. 2009.
Abstract

J. Llibre, M. A. Teixeira.
Limit cycles bifurcating from a 2-dimensional isochronous cylinder.
Appl. Math. Lett., 22(8), 1231-1234. 2009. [DOI]
Abstract

J. Llibre, C. Valls.
Centers for polynomial vector fields of arbitrary degree.
Commun. Pure Appl. Anal., 8(2), 725-742. 2009. [DOI]
Abstract

J. Llibre, C. Valls.
Classification of the centers, their cyclicity and isochronicity for the generalized quadratic polynomial differential systems.
J. Math. Anal. Appl., 357, 427-437. 2009. [DOI]
Abstract

J. Llibre, C. Valls.
Analytic first integrals of the Fitzhugh-Nagumo systems.
Z. Angew. Math. Phys., 60(2), 237-245. 2009. [DOI]
Abstract

J. Llibre, C. Valls.
Classification of the centers and of the isochronous centers for a class of quartic-like systems.
Nonlinear Anal., 71, 3119-3128. 2009. [DOI]
Abstract

J. Llibre, C. Valls.
Classification of the centers, of their cyclicity and isochronicity for two classes of generalized quintic polynomial differential systems.
NoDEA Nonlinear Differential Equations Appl., 16, 657-679. 2009. [DOI]
Abstract

J. Llibre, C. Valls.
Classification of the centers, their cyclicity and isochronicity for a class of polynomial differential systems generalizing the linear systems with cubic homogeneous nonlinearities.
J. Differential Equations, 246, 2192-2204. 2009. [DOI]
Abstract

J. Llibre, C. Valls.
Global analytic first integrals for the simplified multistrain/two-stream model for tuberculosis and dengue fever.
J. Nonlinear Math. Phys., 16(4), 505-516. 2009. [DOI]
Abstract

J. Llibre, H. Wu, J. Yu.
Linear estimate for the number of limit cycles of a perturbed cubic polynomial differential system.
Nonlinear Anal., 70, 419-432. 2009. [DOI]
Abstract

J. Llibre, J. Yu.
On the periodic orbits of the static spherically symmetric Einstein-Yang-Mills equations.
Commun. Math. Phys., 286, 277-281. 2009. [DOI]
Abstract

J. Llibre, X. Zhang.
Darboux theory of integrability in $ C^n$ taking into account the multiplicity.
J. Differential Equations, 246, 541-551. 2009. [DOI]
Abstract

J. Llibre, X. Zhang.
Hopf bifurcation in higher dimensional differential systems via the averaging method.
Pacific J. Math., 240(2), 321-341. 2009. [DOI]
Abstract