1. Aschbacher M., Flag structures on Tits geometries, Geom. Dedicata 14 (1983), 21–32.
2. Brouwer A. E. - Cohen A. M., Some remarks on Tits geometries, Indagationes Mathematicae col. 45 (1983).
3. Brouwer A. E. - Cohen A. M., Computation of some parameters of Lie-geometries (preprint).
4. Brouwer A. E. - Cohen A. M., Local recognition of Tits geometries of classical type, Geom. Dedeicata 20 (1986), 181–199.
5. Buekenhout F., A characterization of polar spaces, Simon Stevin 53 (1973), 3–7.