W. Li, J. Llibre, H. Wu.
Normal forms for almost periodic differential systems.
Ergodic Theory Dynam. Systems, 29, 637-656. 2009.
Abstract

W. Li, J. Llibre, J. Yang, Z. Zhang.
Limit cycles bifurcating from the period annulus of quasi-homogeneous centers.
J. Dyn. Diff. Equat., 21(1), 133-152. 2009.
Abstract

J. Llibre.
A survey on the limit cycles of the generalized polynomial Liénard differential equations.
In Proceedings of Mathematical Models in Engineering, Biology and Medicine Conference on Boundary Value Problems 2008, 224-233. Amer. Inst. Phys, 2009.
Abstract

J. Llibre, P. R. Silva, M. A. Teixeira.
Study of singularities in nonsmooth dynamical systems via singular perturbation.
SIAM J. Appl. Dyn. Syst., 8(1), 508-526. 2009.
Abstract

J. Llibre, A. Makhlouf.
Bifurcation of limit cycles from a 4-dimensional center in 1:n resonance.
J. Comput. Appl. Math., 215, 140-146. 2009. [DOI]
Abstract

J. Llibre, A. Makhlouf.
Limit cycles of polynomial differential systems bifurcating from the periodic orbits of a linear differential system in $\mathbb R^d$.
Bull. Sci. Math., 133, 578-587. 2009.
Abstract

J. Llibre, A. Makhlouf, S. Badi.
3-dimensional Hopf bifurcation via averaging theory of second order.
Discrete Contin. Dyn. Syst., 25, 1287-1295. 2009.
Abstract

J. Llibre, W. Marzantowicz.
Homotopy minimal periods of holomorphic maps on surfaces.
Funct. Approx. Comment. Math., 40(2), 309-326. 2009.
Abstract

J. Llibre, L. F. Mello.
Triple and quadruple nested central configurations for the planar n-body problem.
Phys. D, 238, 563-571. 2009.
Abstract

J. Llibre, L. F. Mello.
New central configurations for the planar 7-body problem.
Nonlinear Anal. Real World Appl., 10(4), 2246-2255. 2009.
Abstract

J. Llibre, M. Messias.
Global dynamics of the Rikitake system.
Phys. D, 238, 241-252. 2009.
Abstract

J. Llibre, R. D. S. Oliveira.
Phase portraits of quadratic polynomial vector fields having a rational first integral of degree 3.
Nonlinear Anal., 70(10), 3549-3560. 2009.
Abstract

J. Llibre, R. D. S. Oliveira.
Erratum to: phase portraits of quadratic polynomial vector fields having a rational first integral of degree 3.
Nonlinear Anal., 71, 6378-6379. 2009.
Abstract

J. Llibre, C. Pantazi.
Darboux theory of integrability for a class of nonautonomous vector fields.
J. Math. Phys., 50, 102705 1-19. 2009.
Abstract

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