Erratum to: Mathematical modelling of two-fluid electro-osmotic peristaltic pumping of an Ellis fluid in an axisymmetric tubeN. Ali, S. Hussain, K. Ullah and O. Anwar BégEur. Phys. J. Plus, 134 6 (2019) 252DOI: https://doi.org/10.1140/epjp/i2019-12789-4