Case C-18/90, Bahia Kziber v. Office National de l’Emploi (ONEM), Preliminary ruling of 31 January 1991, requested by the Cour du travail de LiègeBahia Kziber v. Office National de l’Emploi (ONEM), Preliminary ruling of 31 January 1991, requested by the Cour du travail de LiègeBahia Kziber v. Office National de l’Emploi (ONEM), Preliminary ruling of 31 January 1991, requested by the Cour du travail de Liège