[2] Ewald G.:
Geometry: An Introduction. Wadsworth Publishing Company, Inc., Belmont, California, 1971.
MR 0365322 |
Zbl 0292.50001
[3] Hjelmslev J.: Die natürliche Geometrie. Leipzig, 1923.
[5] Jurga R.:
Some combinatorial properties of conics in the Hjelmslev plane. Math. Slovaca 45 (1995), no. 3, 219-226.
MR 1361814 |
Zbl 0853.05018