Note on Separability of the Werner states in arbitrary dimensions
  Great progress has been made recently in establishing conditions for separability of a particular class of Werner densities on the tensor product space of $n$ $d$--level systems (qudits). In this brief note we complete the process of establishing necessary and sufficient conditions for separability of these Werner densities by proving the sufficient condition for general n and d. 
Arthur O. Pittenger and Morton H. Rubin