"1580","Post-Gutenberg Galaxy: The Fourth Revolution in the Means of Production of Knowledge","The 4th revolution after speech, writing and print, is skywriting (email, hypermail, web-based archiving).","http://cogprints.org/1580/","Harnad, Stevan","UNSPECIFIED"," Harnad, Stevan (1991) Post-Gutenberg Galaxy: The Fourth Revolution in the Means of Production of Knowledge. [Journal (Paginated)] ","","1991"