The nondynamical r-matrix structure of the elliptic   Ruijsenaars-Schneider model with N=2
  We demonstrate that in a certain gauge the elliptic Ruijsenaars-Shneider model with N=2 admits a nondynamical r-matrix structure and the corresponding classical r-matrix is the same as that of its non-relativistic counterpart (Calogero-Moser model) in the same gauge.The relation between our (classical)Lax operator and the Lax operator given by Ruijsenaars is also obtained. 
Bo-yu Hou and Wen-li Yang