Wagner-Kaiser R.; De Maio T.; Sarajedini A., et al. The Void in the Sculptor Group Spiral Galaxy NGC 247. S. 3260–3269. Monthly Notices of the Royal Astronomical Society [online]. 2014-08-07 [cit. 2016-04-12]. Roč. 443, čís. 4, s. 3260–3269. arXiv1407.0584. DOI10.1093/mnras/stu1327. (anglicky)
NASA/IPAC Extragalactic Database: Results for NGC 247 [online]. [cit. 2016-04-12]. Dostupné online. (anglicky)
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Wagner-Kaiser R.; De Maio T.; Sarajedini A., et al. The Void in the Sculptor Group Spiral Galaxy NGC 247. S. 3260–3269. Monthly Notices of the Royal Astronomical Society [online]. 2014-08-07 [cit. 2016-04-12]. Roč. 443, čís. 4, s. 3260–3269. arXiv1407.0584. DOI10.1093/mnras/stu1327. (anglicky)