@article{01730446, title = {Hyperplanes of dual polar spaces of rank 3 with no subquadrangular quad.}, journal = {Advances in Geometry}, volume = {2}, year = {2002}, pages = {107-122}, doi = {10.1515/advg.2002.001}, zbl = {0997.51002}, language = {en}, url = {http://dml.mathdoc.fr/item/01730446} }
Pralle, Harm. Hyperplanes of dual polar spaces of rank 3 with no subquadrangular quad.. Advances in Geometry, Tome 2 (2002) pp. 107-122. doi : 10.1515/advg.2002.001. http://gdmltest.u-ga.fr/item/01730446/