Ray DF Tr. Innovation process in the energy industries Ray DF Tr.; Uhmann L Tr. - Cambridge Cambridge University Press 1979 - xii, 119p. cm. - National Institute of Economic and Social Research Cocasional papers..30 . ISBN: 0521223717 Source: General Book Subjects--Topical Terms: Fuel Dewey Class. No.: X9(F55):84.5.N7, L9