MR3730338 Reviewed de Jeu, Marcel(NL-LEID-MI); Tomiyama, Jun(J-TOKYM) The closure of ideals of ℓ1(Σ) in its enveloping C∗-algebra. (English summary) Adv. Oper. Theory 3 (2018), no. 1, 42–52. 46K10 (47L65 54H20)