Ruffin, Roy J. Principles of macroeconomics / Roy J Ruffin and Paul R.Gregory, - Illinois : Scott, Foresman and Co. , 1983 - xxix, 416p. : ill. ; 27 cm. Includes bibliographical references and index. Subjects--Topical Terms: Economic theoryInternational trade Dewey Class. No.: 330.1 / RUF