Optical solitons for the Calogero-Bogoyavlenskii-Schiff equation in (2 + 1) dimensions with time-fractional conformable derivativeZ. Hammouch, T. Mekkaoui and P. AgarwalEur. Phys. J. Plus, 133 7 (2018) 248DOI: https://doi.org/10.1140/epjp/i2018-12096-8