New Bäcklund transformations of the (2 + 1)-dimensional Burgers system related to residual symmetry Xi-zhong Liu, Jun Yu and Zhi-mei Lou Eur. Phys. J. Plus, 133 3 (2018) 89 Published online: 05 March 2018 DOI: 10.1140/epjp/i2018-11925-0