Nonlinear ion acoustic solitary wave in collisional pair ion plasma with trapped electronsB. Boro, A. N. Dev, B. K. Saikia and N. C. AdhikaryEur. Phys. J. Plus, 136 8 (2021) 831DOI: https://doi.org/10.1140/epjp/s13360-021-01820-2