00298nam a2200097Ia 4500008004100000082001500041100002300056245006600079260004300145300001200188190709s9999    xx            000 0 und d  a338.9 L492  aLebergott, Stanley 0aManpower in economic growth : the American record since, 1800  aNew YorkbMcGraw - Hill Book Co.c1964  axii,561