Entanglement, EPR steering and Gaussian geometric discord in a double cavity optomechanical systems Mohamed Amazioug, Mostafa Nassik and Nabil Habiballah Eur. Phys. J. D, 72 10 (2018) 171 Published online: 05 October 2018 DOI: 10.1140/epjd/e2018-90151-6