%0 Journal Article %A J. Płonka %T On groups in which idempotent reducts form a chain %J Colloquium Mathematicum %D 1974 %P 87-91 %V 29 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.4064/cm-29-1-87-91/ %R 10.4064/cm-29-1-87-91 %G en %F 10_4064_cm_29_1_87_91