[1]   Fu W, Huang L, Tamizhmani KM, Zhang DJ. 2013 Integrability properties of the differential-difference Kadomtsev–Petviashvili hierarchy and continuum limits. Nonlinearity 26, 3197–3229.

[2]   Fu W, Ilangovane R, Tamizhmani KM, Zhang DJ. 2014 Integrability properties of the dispersionless Kadomtsev–Petviashvili hierarchy. J. Math. Phys. 55, 083504.

[3]   Fu W, Qiao ZJ, Sun JW, Zhang DJ. 2015 Continuous correspondence of conservation laws of the semi-discrete AKNS system. J. Nonlinear Math. Phys. 22, 321–341.

[4]   Fu W, Nijhoff FW. 2017 Direct linearizing transform for three-dimensional discrete integrable systems: the lattice AKP, BKP and CKP equations. Proc. Royal Soc. A 473, 20160915.

[5]   Fu W, Nijhoff FW. 2017 On reductions of the discrete Kadomtsev–Petviashvili-type equations. J. Phys. A: Math. Theor. 50, 505203.

[6]   Fu W. 2018 Direct linearisation of the discrete-time two-dimensional Toda lattices. J. Phys. A: Math. Theor. 51, 334001.

[7]   Fu W, Nijhoff FW. 2018 Linear integral equations, infinite matrices, and soliton hierarchies. J. Math. Phys. 59, 071101.

[8]   Fu W. 2020 Direct linearization approach to discrete integrable systems associated with $\mathbb{Z}_\mathcal{N}$ graded Lax pairs. Proc. Royal Soc. A 476, 20200036.

[9]   Fu W, Nijhoff FW. 2021 On nonautonomous differential-difference AKP, BKP and CKP equations. Proc. Royal Soc. A 477, 20200717.