Finding fossil groups: optical identification and X-ray confirmation - Miller, Eric D; Rycoff, Elis; Dupke, Renato A; Oliveira, Claudia Mendes de; Oliveira, Raimundo Lopes de; Proctor, Robert N; Garmire, Gordon P; Koester, Benjamin P; McKay, Timothy A (The Astrophysical Journal, 2012)