%0 Journal Article %A V. V. Tkachuk %T On a cardinal invariant resembling the Souslin number %J Colloquium Mathematicum %D 1987 %P 377-385 %V 55 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.4064/cm-55-2-377-385/ %R 10.4064/cm-55-2-377-385 %G en %F 10_4064_cm_55_2_377_385