- 
								[1]
								C. Z. Yuan et al (Belle Collaboration), Phys. Rev. Lett., 99:182004 (2007)[arXiv:0707.2541[hep-ex]] 
- 
								[2]
								M. Ablikim et al (BESⅢ Collaboration), Phys. Rev. Lett., 114 (9):092003 (2015)[arXiv:1410.6538[hep-ex]] 
- 
								[3]
								B. Aubert et al (BaBar Collaboration), Phys. Rev. Lett., 95:142001 (2005)[hep-ex/0506081] 
- 
								[4]
								B. Aubert et al (BaBar Collaboration), Phys. Rev. Lett., 98:212001 (2007)[hep-ex/0610057] 
- 
								[5]
								X. L. Wang et al (Belle Collaboration), Phys. Rev. Lett., 99:142002 (2007)[arXiv:0707.3699[hep-ex]] 
- 
								[6]
								G. Pakhlova et al (Belle Collaboration), Phys. Rev. Lett., 101:172001 (2008)[arXiv:0807.4458[hep-ex]] 
- 
								[7]
								E. Eichten et al, Phys. Rev. D, 17:3090 (1978); 21:203 (1980); S. Godfrey and N. Isgur, Phys. Rev. D, 32:189 (1985) 
- 
								[8]
								H. X. Chen, W. Chen, X. Liu, and S. L. Zhu, Phys. Rep. 639:1 (2016) 
- 
								[9]
								B. Aubert et al (BaBar Collaboration), Phys. Rev. D, 76:111105 (2007)[hep-ex/0607083] 
- 
								[10]
								B. Aubert et al (BaBar Collaboration), Phys. Rev. D, 79:092001 (2009)[arXiv:0903.1597[hep-ex]] 
- 
								[11]
								P. del Amo Sanchez et al (BaBar Collaboration), Phys. Rev. D, 82:052004 (2010)[arXiv:1008.0338[hep-ex]] 
- 
								[12]
								G. Pakhlova et al (Belle Collaboration), Phys. Rev. D, 77:011103 (2008)[arXiv:0708.0082[hep-ex]] 
- 
								[13]
								K. Abe et al (Belle Collaboration), Phys. Rev. Lett., 98:092001 (2007)[hep-ex/0608018] 
- 
								[14]
								G. Pakhlova et al (Belle Collaboration), Phys. Rev. Lett., 100:062001 (2008)[arXiv:0708.3313[hep-ex]] 
- 
								[15]
								G. Pakhlova et al (Belle Collaboration), Phys. Rev. D, 80:091101 (2009)[arXiv:0908.0231[hep-ex]] 
- 
								[16]
								G. Pakhlova et al (Belle Collaboration), Phys. Rev. D, 83:011101 (2011)[arXiv:1011.4397[hep-ex]] 
- 
								[17]
								V. Zhukova et al (Belle Collaboration), arXiv:1707.09167[hep-ex] 
- 
								[18]
								D. Cronin-Hennessy et al (CLEO Collaboration), Phys. Rev. D, 80:072001 (2009)[arXiv:0801.3418[hep-ex]] 
- 
								[19]
								E. A. Kuraev and V. S. Fadin, Sov. J. Nucl. Phys., 41:466 (1985)[Yad. Fiz. 41:733 (1985)]