Covering morphisms and normal extensions in Galois structures associated with torsion theories
Cahiers de Topologie et Géométrie Différentielle Catégoriques, Tome 50 (2009) no. 3, article no. 1, 18 p. 
@article{CTGDC_2009__50_3_171_0,
     author = {Gran, Marino and Janelidze, George},
     title = {Covering morphisms and normal extensions in {Galois} structures associated with torsion theories},
     journal = {Cahiers de Topologie et G\'eom\'etrie Diff\'erentielle Cat\'egoriques},
     eid = {1},
     pages = {171--188},
     publisher = {Andr\'ee CHARLES EHRESMANN},
     volume = {50},
     number = {3},
     year = {2009},
     mrnumber = {2553538},
     zbl = {1197.18007},
     language = {en},
     url = {http://www.numdam.org/item/CTGDC_2009__50_3_171_0/}
}
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Gran, Marino; Janelidze, George. Covering morphisms and normal extensions in Galois structures associated with torsion theories. Cahiers de Topologie et Géométrie Différentielle Catégoriques, Tome 50 (2009) no. 3, article  no. 1, 18 p. http://www.numdam.org/item/CTGDC_2009__50_3_171_0/

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