Soliton Equations and Their Algebro-Geometric Solutions

F. Gesztesy, H. Holden, J. Michor, and G. Teschl:

Volume II: (1+1)-Dimensional Discrete Models

Cambridge studies in advanced mathematics, Vol. 114
Cambridge University Press, Cambridge, 2008

F. Gesztesy and H. Holden:

Volume I: (1+1)-Dimensional Continuous Models

Cambridge studies in advanced mathematics, Vol. 79
Cambridge University Press, Cambridge, 2003