Nonlinear dust acoustic waves in a self-gravitating and opposite-polarity complex plasma mediumW. F. El-Taibany, S. K. El-Labany, E. E. Behery and A. M. AbdelghanyEur. Phys. J. Plus, 134 9 (2019) 457DOI: https://doi.org/10.1140/epjp/i2019-12827-3