Segre worked on geometric properties invariant under linear transformations, algebraic curves and ruled surfaces studying transformations already considered by Brill, Clebsch, Gordan and Max Noether .
Segre nagtrabaho sa geometriko properties invariant sa ilalim ng guhit transformations, algebraic kurva at pinasiyahan ibabaw pag-aaral transformations na isinasaalang-alang sa pamamagitan ng Brill, Clebsch, Gordan at Max Noether.