%0 Journal Article
%A Gordana Pavlović-Lažetić
%T Inference in a Relation Knowledge-base With two Types of Null Values
%J Publications de l'Institut Mathématique
%D 1993
%P 156 
%V _N_S_54
%N 68
%I mathdoc
%U http://geodesic.mathdoc.fr/item/PIM_1993_N_S_54_68_a18/
%G en
%F PIM_1993_N_S_54_68_a18