Sommerville D. The Elements of Non-Euclidean Geometry

Chicago: The Open Court Publishing Co., 1919. – 274 p.Historical
Elementary Hyperbolic Geometry
Elliptic Geometry
Analytical Geometry
Representations of Non-Euclidean Geometry in Euclidean Space
"Space-Curvature" and the Philosophical Bearing of Non-Euclidean Geometry
Radical Axes, Homothetic Centres, and Systems of Circles
Inversion and Allied Transformations
The Conic