A mass-energy preserving Galerkin FEM for the coupled nonlinear fractional Schrödinger equations Guoyu Zhang, Chengming Huang and Meng Li Eur. Phys. J. Plus, 133 4 (2018) 155 Published online: 20 April 2018 DOI: 10.1140/epjp/i2018-11982-3