Civita, Tullio Levi . A Simplified Presentation of Einstein`s Unified Field Equations / Textual Documents Tullio Levi Civita. - 1st ed. / - London : Blackie & Sons Ltd , 1929. - 22p. : ill ; 22cm . Subjects--Index Terms: Physics Field Equations G-Physics Dewey Class. No.: 530.1 / L 578 Si