Trading blocs, U.S. exports, and world trade / Penelope Hartland-Thunberg. Hartland-Thunberg, Penelope. Commercial policy. International economic relations. HF1411 .H328 382.30973 HAT Includes bibliographies and index. Boulder, Colo. : Westview Press, 1980. 1980. 1980 Text xiv, 197 p. ; eng Westview special studies in international economics and business