%0 Journal Article %A Ralph Seifert %T On prime binary relational structures %J Fundamenta Mathematicae %D 1971 %P 187-203 %V 70 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.4064/fm-70-2-187-203/ %R 10.4064/fm-70-2-187-203 %G en %F 10_4064_fm_70_2_187_203