E. Esmailzadeh et G. Nakhaiejazar, PERIODIC-SOLUTION OF A MATHIEU-DUFFING TYPE EQUATION, International journal of non-linear mechanics, 32(5), 1997, pp. 905-912
It is found that there exists necessary and sufficient conditions for
the existence of at least one periodic solution for a type of parametr
ic second-order ordinary differential equations, known as the Mathieu-
Duffing equation. The correctness of the conditions have been pointed
out by the Schauder's fixed point theorem, and the validity of the ass
umptions has been shown by the analysis of an illustrative example in
non-linear vibration. (C) 1997 Elsevier Science Ltd.