Comments on employing the Riesz-Feller derivative in the Schrödinger equation B. Al-Saqabi, L. Boyadjiev and Yu. Luchko Eur. Phys. J. Special Topics, 222 8 (2013) 1779-1794 Published online: 07 October 2013 DOI: 10.1140/epjst/e2013-01963-3