Thereafter, he went to the University of Rome, where he studied under Tullio Levi-Civita, obtaining his doctorate on November 5, 1924, with thesis Sopra una teorema di Weierstrass e le sue applicazioni alla stabilità.

In 1927–1928, he was awarded a Rockefeller Foundation scholarship to study in France and the United States, where he was in a contact with Élie Cartan and Oswald Veblen.

In 1939, he moved to the University of Bucharest, where he was appointed Head of the Geometry and Topology department in 1948, a position he held until his retirement in 1970.

His work covers a whole range of modern geometry, from the classical theory of surfaces, to the notion of non-holonomic spaces, which he discovered.

In 1928 he gave an invited talk at the International Congress of Mathematicians in Bologna, titled Parallelisme et courbure dans une variété non holonome.