1. Belle Collaboration, J. Kaneko et al., Phys. Rev. Lett. 90, 021801 (2003) [hep-ex/0208029]
2. BABAR Collaboration, B. Aubert et al., Phys. Rev. Lett. 93, 081802 (2004) [hep-ex/0404006]
3. BaBar Collaboration, B. Aubert et al., hep-ex/0507005, contributed to 22nd International Symposium on Lepton–Photon Interactions at High Energy (LP 2005), Uppsala, Sweden, 30 June–5 July 2005
4. Belle Collaboration, K. Abe et al., hep-ex/0410006, presented at 32nd International Conference on High-Energy Physics (ICHEP 04), Beijing, China, 16–22 August 2004
5. Belle Collaboration, K. Abe et al., hep-ex/0508009