Abdelsalam Abou Zayda  , 
    On Properties of the Geometry D<SUB>n, n-2</SUB>,
    Journal of Modern Mathematics and Statistics,
    Volume 2,Issue 4,
    2008,
    Pages 129-133,
    ISSN 1994-5388,
    jmmstat.2008.129.133,
    (https://makhillpublications.co/view-article.php?doi=jmmstat.2008.129.133)
    Abstract: We give a general case of the geometries D<SUB>5, 3</SUB> and D<SUB>6, 4</SUB>, it is a point-line geometry of type D<SUB>n, n-2</SUB> (F), n<SUB> </SUB> 5. We present a diagram and a complete definition of all varieties of such geometry to be isomorphic to the classical polar space of type  <SUP>+</SUP> (2n, F). This study includes a characterization of the geometry and the most important properties will be investigated; we prove that the geometry is a strong parapolar with diameter equal n-1.
    Keywords: Parapolar space;classical polar space;strong geometry;Dn; n-2