%0 Journal Article %A Joan Bagaria %A Saharon Shelah %T On partial orderings having precalibre-$\aleph _1$ and fragments of Martin's axiom %J Fundamenta Mathematicae %D 2016 %P 181-197 %V 232 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.4064/fm232-2-6/ %R 10.4064/fm232-2-6 %G en %F 10_4064_fm232_2_6