%0 Journal Article %A Bruen, A. %A Fisher, J. C. %T Spreads which are Not Dual Spreads %J Canadian mathematical bulletin %D 1969 %P 801-803 %V 12 %N 6 %U http://geodesic.mathdoc.fr/articles/10.4153/CMB-1969-103-7/ %R 10.4153/CMB-1969-103-7 %F 10_4153_CMB_1969_103_7