Barzun, Jacques The modern researcher / Jacques Barzun, Henry F. Graff - 3rd. ed. - New York : Harcourt Brace Jovanovich , 1970 - xix, 378p. : ill. ; 23 cm. Includes index ISBN: 0155625511X Subjects--Topical Terms: HistoriaMetodología (Historia) LC Class. No.: D 13 / B39 1970