Baker H.F. Principles of geometry. Volume 1. Foundations

Cambridge: The University Press, 1922. — 196 p.Abstract Geometry
Propositions of Incidence
The correspondence of the points of two lines. Pappus' theorem
Introduction of algebraic symbolsReal Geometry
The Propositions of Incidence. Introduction of a plane, and of a space
The extension of the Real Geometry by means of Postulated Elements
A deduction of Pappus' theorem from the extended Real GeometryAbstract Geometry, resumed
Related spaces; justification of the symbols. Geometrical assumption for imaginary elements; replacement of imaginary elements by series of real elements