J. Dong, M. Albrecht, D. J. Ambrose et al.|Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields|2014
M. Ablikim, L. Fava, M. N. Achasov et al.|Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields|2013