@article{1103408998,
author = {Blokhuis, Aart and O'Keefe, Christine M. and Payne, Stanley E. and Storme, Leo and Wilbrink, Henny},
title = {Covers of {${\rm PG}(3,q)$} and of finite generalized quadrangles},
journal = {Bull. Belg. Math. Soc. Simon Stevin},
volume = {5},
number = {5},
year = {1998},
pages = { 141-157},
language = {en},
url = {http://dml.mathdoc.fr/item/1103408998}
}
Blokhuis, Aart; O'Keefe, Christine M.; Payne, Stanley E.; Storme, Leo; Wilbrink, Henny. Covers of {${\rm PG}(3,q)$} and of finite generalized quadrangles. Bull. Belg. Math. Soc. Simon Stevin, Tome 5 (1998) no. 5, pp. 141-157. http://gdmltest.u-ga.fr/item/1103408998/