Kristen B. W. McQuinn et al.Accurate Distances to Important Spiral Galaxies: M63, M74, NGC 1291, NGC 4559, NGC 4625, and NGC 5398.„The Astronomical Journal”.154(2),s.51,2017. DOI: 10.3847/1538-3881/aa7aad. arXiv:1706.06586.(ang.).
Kristen B. W. McQuinn et al.Accurate Distances to Important Spiral Galaxies: M63, M74, NGC 1291, NGC 4559, NGC 4625, and NGC 5398.„The Astronomical Journal”.154(2),s.51,2017. DOI: 10.3847/1538-3881/aa7aad. arXiv:1706.06586.(ang.).