1. Dai, B., Terng, C. L., Uhlenbeck, K.: On the space-time monopole equations. Surv. Diff. Geom., 10, 1–30 (2006)
2. Villarroel, J.: The inverse problem for Ward’s system. Stud. Appl. Math., 83, 211–222 (1990)
3. Fokas, A. S., Ioannidou, T. A.: The inverse spectral theory for the Ward equation and for the 2+1 chiral model. Comm. Appl. Anal., 5, 235–246 (2001)
4. Hitchin, N. J.: Riemann surfaces and integrable systems, in Integrable System. Oxf. Grad. Texts Math., 2, 11–52 (1999)
5. Pressley, A., Segal, G.: Loop Groups, Oxford University Press, 1986