SamoilenkoA. M.; SamoilenkoV. G.; SidorenkoY. M. Hierarchy of the Kadomtsev-Petviashvili equations under nonlocal constraints: Many-dimensional generalizations and exact solutions of reduced system. Ukrains’kyi Matematychnyi Zhurnal, v. 51, n. 1, p. 78–97, 25 Jan. 1999.