Barnard, R., Stiele, H., Hatzidimitriou, D., Kong, A. K. H., Williams, B. F., Pietsch, W., et al. (2008). New XMM-Newton analysis of three bright X-ray sources in M31 globular clusters, including a new black hole candidate. The Astrophysical Journal, 689(2), 1215-1221. doi:10.1086/592594.