"Géométrie projective." . . . . . . . . . . "The Principles of projective geometry applied to the straight line and conic, by J. L. S. Hatton" . . . . . . . . . "The Principles of Projective Geometry applied to the straight line and conic"@en . "The Principles of Projective Geometry Applied to the Straight Line and Conic" . . "The principles of projective geometry" . . . . . . . "The principles of projective geometry applied to the straight line and conic" . "The principles of projective geometry applied to the straight line and conic"@en . . . "Geometría proyectiva." . .