1. On a combinatorial generalization of 27 lines associated with a cubic surface;Ahrens;J. Austral. Math. Soc.,1969
2. Generalized hexagons and BLT-sets;Bader,1993
3. Derivation of flocks of quadratic cones;Bader;Forum Math.,1990
4. Principles of Geometry;Baker,1921
5. On the structure of generalized quadrangles;Benson;J. Algebra,1970