Gazeau-Klauder coherent states for the partner potentials of the trigonometric symmetric scarf type H. Fakhri, A. Kianfar and M. Sayyah-Fard Eur. Phys. J. Plus, 131 2 (2016) 43 Published online: 23 February 2016 DOI: 10.1140/epjp/i2016-16043-5