00378nam a2200121Ia 4500020001500000082002300015100003700038245008500075260004800160300001300208500000500221700003000226  a0521084091  a338.6042bSh548.SM  aShepherd, J. F. and Walton G. M.  aShipping maritime trade and the economic development of colomial North Americab  aCambridgebCambridge University Pressc1972  ax, 255p.  a  aWalton, G. M. ; jt. auth.