1. “Crystallographic and magnetic structures of Y0.8Sr2.2Mn2GaO8-: a new vacancy-ordered perovskite structure”. Gillie LJ, Palmer HM, Wright AJ, Hadermann J, Van Tendeloo G, Greaves C, The journal of physics and chemistry of solids 65, 87 (2004).   http://doi.org/10.1016/j.jpcs.2003.08.012