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O.G. Richter, « The Hydra I cluster of galaxies. V.A catalogue of galaxies in the cluster area. », Astronomy and Astrophysics Supplement Series, vol. 77, , p. 237-256 (ISSN0365-0138, Bibcode1989A&AS...77..237R, lire en ligne)
articles.adsabs.harvard.edu
O.G. Richter, « The Hydra I cluster of galaxies. V.A catalogue of galaxies in the cluster area. », Astronomy and Astrophysics Supplement Series, vol. 77, , p. 237-256 (ISSN0365-0138, Bibcode1989A&AS...77..237R, lire en ligne)
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portal.issn.org
O.G. Richter, « The Hydra I cluster of galaxies. V.A catalogue of galaxies in the cluster area. », Astronomy and Astrophysics Supplement Series, vol. 77, , p. 237-256 (ISSN0365-0138, Bibcode1989A&AS...77..237R, lire en ligne)