Silberstein, Ludwik, 1872- The size of the universe : attempts at a determination of the curvature radius of spacetime / by Ludwik Silberstein. - [London] : Oxford University Press, 1930. - viii, 215, [1] p. : tables. diagrs. ; 21 cm. Includes bibliographical foot-notes. LCCN: no 30000005 Subjects--Topical Terms: Relativity (Physics) LC Class. No.: QC6 / .S48