L.M. Buravtseva, O.S. Pyshkin, M.A. Strzhemechny, and A.A. Avdeenko, Phosphorescence of vitreous 2-bromobenzophenone, Low Temp. Phys. 34, (2008) [Fiz. Nizk. Temp. 34, 587-591, (2008)] DOI: https://doi.org/10.1063/1.2920177.