Popovici, Julian Graduäri simple Jordan si Lis considerata in geometria diferentiala. - Bucarest (Rumānia): Editura Academiei Republicii Socialiste Romania, 1971. - 191 p.: 21 cm. Bibliography: p. [133]-136. LCCN: 76881683 Subjects--Topical Terms: Geometry, Differential.Clifford algebras. Dewey Class. No.: 516.36 / P829g