-
[1]
. Polyakov A M .Phys.Lett.,1980 ,B103:207 2. LIAO H C ,Mansfield P .Nucl.Phys.Lett.,1995,B359:1183. Polyakov A M. Phys.Lett.,1980 ,B103:211 4. Arvis J F .Nucl.Phys.,1983,B212 :151 5. Babelon O .Nucl.Phys.,1985,B258:6806. Bowcock P ,Corrigan E ,Dorey P E Nucl,Phys.,1995,B445:469 7. Schulze J .hep–th/96021778. Leznov A N ,Saveliev M V .Lett.Math .Phys.,1979,3:207;4899. CHAOL ,HOUBoYu .Annals.Phys.,1994 ,230 :1– 2010. CHAO L ,QU C Z .Int .J.Phys.,1997,36 (7) :111–11811. Leznov A N ,Saveliev M V .Lett.Math .Phys .,1982 ,6:505 12. Leznov A N .Phys.Lett.,1978,B79:294 ;Commun .Math .Phys.,1980 ,74 :1537–1542 13. Babelon O .Phys.Lett.,1988,B215:523;Phys.Lett.,1991,B260 :81