Coupled oscillators in non-commutative phase space: Path integral approach L. Khiari, T. Boudjedaa, A. Makhlouf and M. T. Meftah Eur. Phys. J. Plus, 134 8 (2019) 396 Published online: 22 August 2019 DOI: 10.1140/epjp/i2019-12770-3