Erratum to : “The finite free extension of artinian K -algebras with the strong Lefschetz property” [Rend. Sem. Mat. Univ. Padova 110 (2003), 119–146] Tadahito Harima, Junzo Watanabe (2004) Rendiconti del Seminario Matematico della Università di Padova
Exact sequences of pairs in commutative rings R. Kiełpiński, G. Simson, A. Tyc (1978) Fundamenta Mathematicae