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Rosse, Earl of (1846). "On the nebula 25 Herschel, or 61 [should read: 51] of Messier's catalogue". Report of the Fifteenth Meeting of the British Association for the Advancement of Science; Held at Cambridge in June 1845 § Notices and Abstracts of Miscellaneous Communications to the Sections. Report of the ... Meeting of the British Association for the Advancement of Science (1833): 4.
Ferrarese, L.; Ford, H. C.; Huchra, J.; Kennicutt Jr., R. C.; et al. (2000). "A Database of Cepheid Distance Moduli and Tip of the Red Giant Branch, Globular Cluster Luminosity Function, Planetary Nebula Luminosity Function, and Surface Brightness Fluctuation Data Useful for Distance Determinations". Astrophysical Journal Supplement. 128 (2): 431–459. arXiv:astro-ph/9910501. Bibcode:2000ApJS..128..431F. doi:10.1086/313391. S2CID121612286.
skyandtelescope.com
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