Bäcklund transformations and nonlinear wave solutions for an extended (2+1)-dimensional Kadomtsev–Petviashvili equationGuo-Hong Yang, Xue-Hui Zhao and Zhong-Zhou LanEur. Phys. J. Spec. Top., (2025) 1-12DOI: https://doi.org/10.1140/epjs/s11734-025-01853-z