“…Such a treatment has been already performed successfully to selected problems with various potentials [8,9,14]. Vibrations of a single Duffing oscillator have got a large bibliography [1,2,3,4,5,6,8,9,10,11,12,13,14,15,16,17,18]. In the last decade coupled Duffing oscillators [19,20,21,22,23] with numerous modifications to potential and forcing parts have been studied.…”