%0 Journal Article %A Alexopoulos, G. %T A Lower Estimate for Central Probabilities on Polycyclic Groups %J Canadian journal of mathematics %D 1992 %P 897-910 %V 44 %N 5 %U http://geodesic.mathdoc.fr/articles/10.4153/CJM-1992-055-8/ %R 10.4153/CJM-1992-055-8 %F 10_4153_CJM_1992_055_8