Complex Ginzburg-Landau equation for self-oscillatory systems under   amplitude modulated forcing in a 1:1 resonance
  The dynamics of self-oscillatory extended systems, resonantly forced at a frequency close to that of the natural oscillations (1:1 resonance), is shown to be universally described by a complex Ginzburg-Landau equation containing an inhomogeneous term. The case of amplitude modulated forcing is considered, which generalizes previous studies. Application to the two-frequency forcing in a 1:1 resonance is considered as an example. 
German J. de Valcarcel