Influence of non-integer-order derivatives on unsteady unidirectional motions of an Oldroyd-B fluid with generalized boundary conditionsA. A. Zafar, M. B. Riaz, N. A. Shah and M. A. ImranEur. Phys. J. Plus, 133 3 (2018) 127DOI: https://doi.org/10.1140/epjp/i2018-11981-4