REFERENCES
- J. L. Coolidge, A history of geometrical methods, Dover, 1963. Chapter IV, pp. 68–87. (“Nice summary”)
- N. V. Efimov, Higher geometry, Mir, 1980. Chaper 8, pp. 474–528. (Useful beyond the needs of this essay.)
- H. Eves, Great moments in mathematics, DME #7, MAA, 1983. Lectures 26 and 27. (Fine elementary account.)
- V. F. Kagan, Foundations of geometry, GITTL, Moscow, Parts I and II. (In Russian.) Lectures 26 and 27. (Included because Part II contains the Lopshits essay mentioned on p. 465.)
- J. Stillwell, Mathematics and its history, Springer, 1989. Chapter 17, pp. 255–274.
- I. M. Yaglom, Geometric transformations III, NML #24, MAA, 1973. Introduction and Supplement, pp. 103–135. (Supplement contains detailed elementary account of Klein's disk model.)