↑ Anna Frebel; และคณะ (2007), "Discovery of HE 1523–0901, a Strongly r-Process-enhanced Metal-poor Star with Detected Uranium", Astrophysical Journal, 660: L117, doi:10.1086/518122 Text " journal " ignored (help); Explicit use of et al. in: |author= (help)
↑ Frebel, A.; Norris, J. E.; Christlieb, N.; Thom, C.; Beers, T. C.; Rhee, J. (May 11, 2007). "Nearby Star Is A Galactic Fossil". Science Daily. สืบค้นเมื่อ 2007-05-10.CS1 maint: multiple names: authors list (link)
