The Hubble Space Telescope Survey of M31 Satellite Galaxies. II. The Star Formation Histories of Ultrafaint Dwarf Galaxies oleh Alessandro Savino, Daniel R. Weisz, Evan D. Skillman, Andrew Dolphin, Andrew A. Cole, Nitya Kallivayalil, Andrew Wetzel, Jay Anderson, Gurtina Besla, Michael Boylan-Kolchin, Thomas M. Brown, James S. Bullock, Michelle L. M. Collins, M. C. Cooper, Alis J. Deason, Aaron L. Dotter, Mark Fardal, Annette M. N. Ferguson, Tobias K. Fritz, Marla C. Geha, Karoline M. Gilbert, Puragra Guhathakurta, Rodrigo Ibata, Michael J. Irwin, Myoungwon Jeon, Evan N. Kirby, Geraint F. Lewis, Dougal Mackey, Steven R. Majewski, Nicolas Martin, Alan McConnachie, Ekta Patel, R. Michael Rich, Joshua D. Simon, Sangmo Tony Sohn, Erik J. Tollerud, Roeland P. van der Marel