C. Li, J. Llibre.
The cyclicity of period annulus of a quadratic reversible Lotka-Volterra system.
Nonlinearity, 22, 2971-2979. 2009. [DOI]
Abstract

W. Li, J. Llibre, H. Wu.
Polynomial and linearized normal forms for almost periodic differential systems.
J. Difference Equ. Appl., 15(10), 927-948. 2009. [DOI]
Abstract

W. Li, J. Llibre, H. Wu.
Normal forms for almost periodic differential systems.
Ergodic Theory Dynam. Systems, 29, 637-656. 2009. [DOI]
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. [DOI]
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.
Preface [The Fifth International Symposium on Hamiltonian Systems and Celestial Mechanics ({HAMSYS}-2008)].
Qual. Theory Dyn. Syst., 8(2), 207-208. 2009. [DOI] (Held in Guanajuato, July 7--11, 2008)

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. [DOI]
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 $ R^d$.
Bull. Sci. Math., 133, 578-587. 2009. [DOI]
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. [DOI]
Abstract

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

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

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

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

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