1. Brouwer, A. E.: Private communication, 1981.
2. Brouwer, A. E. and Wilbrink, H. A.: Ovoids and fans in the generalized quadrangleQ(4, 2),Geom. Dedicata 36 (1990), 121?124.
3. De Clerck, F. and Herssens, G.: Flocks of the quadratic cone in PG(3,q) forq small,Reports of the CAGe Project 8 (1993), 1?75.
4. Fellagara, G.: Gli ovaloidi di uno spazio tridimensionale di Galois di ordine 8,Atti Accad. Naz. Lincei Rend. 32 (1962), 170?176.
5. Hirschfeld, J. W. P.:Finite Projective Spaces of Three Dimensions, Clarendon Press, Oxford, 1985.