Central extensions of the alternating group as Galois groups

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Departament d'Àlgebra i Geometria, Facultat de Matemàtiques, Universitat de Barcelona, Gran Via de les Corts Catalanes 585, 08007 Barcelona, Spain

T. Crespo, Explicit construction of Ãₙ-type fields, J. Algebra 127 (1989), 452-461.
T. Crespo, Explicit solutions to embedding problems associated to orthogonal Galois representations, J. Reine Angew. Math. 409 (1990), 180-189.
T. Crespo, Extensions de Aₙ par C₄ comme groupes de Galois, C. R. Acad. Sci. Paris 315 (1992), 625-628.
A. Fröhlich, Orthogonal representations of Galois groups, Stiefel-Whitney classes and Hasse-Witt invariants, J. Reine Angew. Math. 360 (1985), 84-123.
J.-P. Serre, L'invariant de Witt de la forme Tr(x²), Comment. Math. Helv. 59 (1984), 651-676.