Coexistence of Periodic, Chaotic and Hyperchaotic Attractors in a System Consisting of a Duffing Oscillator Coupled to a van der Pol Oscillator. - Sosthene Tsamene Tanekou; Janarthanan Ramadoss; Jacques Kengne; Germaine Djuidje Kenmoe; Karthikeyan Rajagopal (Int. J. Bifurc. Chaos, 2023)