%0 Journal Article %A M. G. Stone %T Proper congruences do not imply a modular congruence lattice %J Colloquium Mathematicum %D 1971 %P 25-27 %V 23 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.4064/cm-23-1-25-27/ %R 10.4064/cm-23-1-25-27 %G en %F 10_4064_cm_23_1_25_27