1. A.Beutelspacher, A Generalization of Dembowski's Theorem on Semi-planes. To appear in Geom. Dedic.
2. P. Dembowski, Semiaffine Ebenen. Arch. Math.13, 120?131 (1962).
3. P.Dembowski, Finite Geometries. Berlin-Heidelberg-New York 1968.
4. D. R. Hughes andF. C. Piper, On Resolutions and Bose's Theorem. Geom. Dedic.5, 129?133 (1976).
5. M. Oehler, Endliche biaffine Inzidenzebenen. Geom. Dedie.4, 419?436 (1975).