Review on B^0- \bar{\rm \bf{B^0}} mixing and b-lifetimes measurements at   CDF/LEP/SLD
  A review of the results on B^0- \bar {\rm B^0} mixing and b-lifetimes obtained by CDF, LEP and SLD collaborations is presented with special emphasis on B^0_s- \bar {{\rm B}^0_s} mixing. 
Achille Stocchi