%0 Journal Article %A Xiaofa Chen %A Xiao-Wu Chen %T The lower extension groups and quotient categories %J Comptes Rendus. Mathématique %D 2019 %P 832-840 %V 357 %N 11-12 %I Elsevier %R 10.1016/j.crma.2019.11.006 %G en %F CRMATH_2019__357_11-12_832_0