A New Model-free Based Proportional Reduced-order Observer Design for the synchronization of Lorenz System.- A Model-free Sliding Observer to Synchronization Problem Using Geometric Techniques.- Experimental Synchronization by Means of Observers.- Synchronization of an Uncertain Rikitake System With Parametric Estimation.- Secure Communications and Synchronization via Sliding-mode Observer.- Synchronization and Anti-Synchronization of Chaotic Systems: A Differential and Algebraic Approach.- Synchronization of Chaotic Liouvillian Systems. An Application to Chua's Oscillator.- Synchronization of Partially Unknown Nonlinear Fractional Order Systems.- Generalized Synchronization via the Differential Primitive Element.- Generalized Synchronization for a Class of Non-Differentially Flat and Liouvilion Chaotic Systems.- Generalized Multi-synchronization by Means of a Family of Dynamical Feedbacks.- Fractional Generalized Synchronization in Nonlinear Fractional Order Systems Via a Dynamical Feedback.- An Observer for a Class of Incommensurate Fractional Order Systems.- Index.