researchgate.net / A Lack of Planets in 47 Tucanae from a Hubble Space Telescope Search; Authors: Ronald L. Gilliland, T. M. Brown, Puragra Guhathakurta, A. Sarajedini, Eugene Frank Milone, M. D. Albrow, N. R. Baliber, Hans Bruntt, A. Burrows, D. Charbonneau, P. Choi, W. D. Cochran, P. D. Edmonds, S. Frandsen, J. H. Howell, Dung Cheng Lin, G. W. Marcy, M. Mayor, D. Naef, S. Sigurdsson, Russell Stagg, D. A. Vandenberg, Steven Vogt and M. D. Williams. The Astrophysical Journal 545(1):L47 | December 2008
