1. B. Aubert et al. [BaBar Collaboration], Phys. Rev. Lett. 91, 171802 (2003)
2. K.F. Chen et al. [Belle Collaboration], Phys. Rev. Lett. 91, 201801 (2003)
3. A.K. Alok, A. Datta, A. Dighe, M. Duraisamy, D. Ghosh, D. London, J. High Energy Phys. 11, 121 (2011)
4. A. Datta, A.V. Gritsan, D. London, M. Nagashima, A. Szynkman, Phys. Rev. D 76, 034015 (2007)
5. T. Aaltonen et al. [CDF Collaboration], Phys. Rev. Lett. 107, 261802 (2011)