1. Dynamic Stability of Elastic Systems;Bolotin,1964
2. On the vibrations of summed and differential types under parametric excitation;Yamamoto;Memoirs of the Faculty of Engineering,1970
3. Linear Differential Equations with Periodic Coefficients (two volumes);Yakubovich,1975
4. Einführung in die Berechnung parametererregter Schwingungen;Eicher,1981
5. Introduction to Linear Parametric and Nonlinear Vibrations;Cartmell,1990