Book Reviews : Paul Johnson & Klaus F. Zimmermann (Eds.): Labour Market in an Ageing Europe. Cambridge: Cambridge University Press, 1993. Martin Kohli, Martin Rein, Anne-Marie Guillemard & Herman Van Gunsteren (Eds.): Time for Retirement: Comparative Studies of Early Exit From the Labour Force. Cambridge: Cambridge University Press, 1991. Frieder Naschold & Bert De Vroom (Eds.): Regulating Employment and Welfare: Com Pany and National Policies of Labour Force Participation at the End of Worklife in Industrial Countries. Berlin: De Gruyter, 1993