Hartland-Thunberg, Penelope. Trading blocs, U.S. exports and world trade / Penelope Hartland-Thunberg. - Boulder : Westview Press, c 1980. - xiv, 197 p. : ills ; 24 cm. - Westview special studies in international economics and business. . Includes index. 318 318 ISBN: 0-89158-967-8 Subjects--Topical Terms: Commercial policy. Dewey Class. No.: 382.0973 / H255t