1.K Chlenbeck.Harmonic Maps into Lie Groups CChs:icalSolutions of the Chiral ModeD. J Diff Geom, 1989, 30;1-50;

2.M A Guest Y Ohnita. Group Actions and Deformations for Harmonic Maps.J Math Soc Japan, 1993, 45C4); 671-704;

3.A N Pressley,G Segal. Loop Groups.Oxford Cniver:ity Press, 1986;

4.M J Bergvelt. M A Guest. Action of Loop Groups on Harmonic Maps. frans of Amer Math Soc, 1991, 326(2): 861-886;

5.J C Wood.The L,xplicit Constmction and Pammetrization of Harmonic fwrrspheres in the Cnitary Group. Proc London Math Soc,1989, 58: 608-624;

6.F E Burstalh M A Guest.Hannonic fwo-spheres in Compact SymmetricSpaces, Revisited. Math Ann, 1997, 309: 541-572;

7. J Dorfmeister, f PediG H Wu. Weierstral Type Representation of Harmonic Maps into Symmetric Spaczs. Comet in AnalAnd Geom, 1998, 6(4): 633-668;

8.W Fulton, RLazarsfeld.On the Connectedness of Degneracy Loci and Special Divisors. Acta Math, 1981, 146; 271-283;

9.M Narnba. farniles of Meromoxphic tumtions on Compact Riemann Surfaces. Lecture Notes in math, 1979, 146;

10.G W Towsley. Conformal Deformations of Meromoxphic Funckions;[ph.d.Thesis],Cniversity of Rochester, 1975;

11.F L, Burstalh F Pedt. Dressing Orbits of Harmonic Maps. J Duke Math, 1995, 80(2): 353-382.