Cayley parametrization and the rotation group over a non-archimedean   pythagorean field
  Using Cayley transform, we show how to construct rotation matrices \emph{infinitely near} the identity matrix over a non-archimedean pythagorean field. As an application, an alternative way to construct non-central proper normal subgroups of the rotation group over such fields is provided. 
M. G. Mahmoudi
math.GR