Beta derivative applied to dark and singular optical solitons for the resonance perturbed NLSE Abdullahi Yusuf, Mustafa Inc, Aliyu Isa Aliyu and Dumitru Baleanu Eur. Phys. J. Plus, 134 9 (2019) 433 Published online: 09 September 2019 DOI: 10.1140/epjp/i2019-12810-0