A Characterization of Buildings of a Spherical Type. - Guy Hanssens (Eur. J. Comb., 1986)

Hjelmslev-quadrangles of level n. - Guy Hanssens; Hendrik Van Maldeghem (J. Comb. Theory A, 1990)

Polarized Spaces of Polar Rank Three Which are Locally a Direct Product. - Guy Hanssens (Eur. J. Comb., 1991)