A classification of a class of \(C_ 3\) geometries
The following theorem is proved: Suppose that S is a geometry of type \(C_ 3\) in which any line is incident with precisely two planes. Then S is either a building or a quotient of a building by a group of automorphisms of order 2. The author provides a list of all these geometries.
scientific article; zbMATH DE number 4013419