1. Allgemeine Theorie Der Stabilität Erzwungener Schwingungen Elastischer Körper;Mettler;Ing. Arch.,1949
2. Asymptotic Methods in the Theory of Non-linear Oscillations;Bogoliubov,1961
3. The Dynamic Stability of Elastic Systems;Bolotin,1964
4. Stabilíty and vibrations problems of mechanical systems under harmonic excitation;Mettler,1965
5. Parametric combination resonance (of the second kind) in non-linear systems;Piszczek;Rozprowy Inzynierskie,1960