%0 Journal Article %A Xiazhi Hao %T Nonlocal symmetries of some nonlinear partial differential equations with third-order Lax pairs %J Teoretičeskaâ i matematičeskaâ fizika %D 2021 %P 139-148 %V 206 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/item/TMF_2021_206_2_a0/ %G ru %F TMF_2021_206_2_a0