This book contains recent contributions in the field of waves propagation and stability in continuous media. The volume is the sixth in a series published by World Scientific since 1999.Contents:Analysis of an Electric Network Containing Multi-Dimensional Semiconductor Devices (G Alì & N Rotundo)Quantum Modeling of Love Affirs (F Bagarello & F Oliveri)Kinetic Equations for Economic Sciences (M Bisi & C Brugna)On a Multi-Temperature Mixture Model for Flame Structure (F Brini)The Davey-Stewartson Equation in a Complex Plasma (P Carbonaro)Einstein constraints on a Characteristic Cone (Y Choquet-Bruhat et al.)Exact Internal Waves of a Boussinesq System (H Y Nguyen et al.)Long-Wavelength Instabilities in Binary Fluid Layers (P Falsaperla & G Mulone)Asymmetry Effects in Viscoresistive Magnetic Reconnection (C Tebaldi et al.)Stability of a Prey-Predator Model with Behavior Changes (W Wang)and other papersReadership: Students and researchers in mathematical physics.