Seidenberg, Roderick Posthistoric man an inquiry. - North Carolina press,1950 - ix, 244 p. 20 cm. - A Viking compass book . Includes bibliographical references. ISBN: 0670004057 LCCN: evl30016921 //r90 Subjects--Topical Terms: CivilizationProgress. LC Class. No.: HM101 / .S34 1950 Dewey Class. No.: 301.24