Pappian affine Klingenberg planes
If the epimorphic image \(\alpha(\Omega)\) of an affine Klingenberg plane \((\Omega, \alpha)\) is a Fano plane then three configuration conditions (including a Pappus-like theorem) imply that \(\Omega\) is isomorphic to the affine Klingenberg plane over a commutative local ring \(R\), where \(1 + 1\) is a non-unit. The corresponding result for the case that \(\alpha(\Omega)\) is not a Fano plane has been proved by \textit{H. Mäurer} and the author in Ann. Discrete Math. 37, 281-291 (1988; Zbl 0652.51008).
scientific article; zbMATH DE number 739187