Christopher Usher; Caroline Foster; Jean Brodie; Jay Strader; Duncan A. Forbes; Nicola Pastorello; Aaron J. Romanowsky; Jacob A. Arnold (). „The SLUGGS survey: exploring the metallicity gradients of nearby early-type galaxies to large radii”. Monthly Notices of the Royal Astronomical Society (în engleză). 442 (2): 1003–1039. arXiv:1405.2338. Bibcode:2014MNRAS.442.1003P. doi:10.1093/MNRAS/STU937. WikidataQ59756686.
Christopher Usher; Caroline Foster; Jean Brodie; Jay Strader; Duncan A. Forbes; Nicola Pastorello; Aaron J. Romanowsky; Jacob A. Arnold (). „The SLUGGS survey: exploring the metallicity gradients of nearby early-type galaxies to large radii”. Monthly Notices of the Royal Astronomical Society (în engleză). 442 (2): 1003–1039. arXiv:1405.2338. Bibcode:2014MNRAS.442.1003P. doi:10.1093/MNRAS/STU937. WikidataQ59756686.
Christopher Usher; Caroline Foster; Jean Brodie; Jay Strader; Duncan A. Forbes; Nicola Pastorello; Aaron J. Romanowsky; Jacob A. Arnold (). „The SLUGGS survey: exploring the metallicity gradients of nearby early-type galaxies to large radii”. Monthly Notices of the Royal Astronomical Society (în engleză). 442 (2): 1003–1039. arXiv:1405.2338. Bibcode:2014MNRAS.442.1003P. doi:10.1093/MNRAS/STU937. WikidataQ59756686.
Christopher Usher; Caroline Foster; Jean Brodie; Jay Strader; Duncan A. Forbes; Nicola Pastorello; Aaron J. Romanowsky; Jacob A. Arnold (). „The SLUGGS survey: exploring the metallicity gradients of nearby early-type galaxies to large radii”. Monthly Notices of the Royal Astronomical Society (în engleză). 442 (2): 1003–1039. arXiv:1405.2338. Bibcode:2014MNRAS.442.1003P. doi:10.1093/MNRAS/STU937. WikidataQ59756686.