- 
								[1]
								T. Barnes and E. S. Swanson, Phys. Rev. D, 46: 131 (1992) 
- 
								[2]
								E. S. Swanson, Ann. Phys. (N.Y.), 220: 73 (1992) 
- 
								[3]
								T. Barnes, E. S. Swanson, and J. Weinstein, Phys. Rev. D, 46: 4868 (1992) 
- 
								[4]
								T. Barnes, N. Black, and E. S. Swanson, Phys. Rev. C, 63: 025204 (2001) 
- 
								[5]
								G. Colangelo, J. Gasser, and H. Leutwyler, Nucl. Phys. B, 603: 125 (2001) 
- 
								[6]
								A. Dobado, M. J. Herrero, and T. N. Truong, Phys. Lett. B, 235: 134 (1990) 
- 
								[7]
								A. Dobado and J. R. Peláez, Phys. Rev. D, 56: 3057 (1997) 
- 
								[8]
								F. Guerrero and J. A. Oller, Nucl. Phys. B, 537: 459 (1999) 
- 
								[9]
								A. G. Nicola and J. Peláez, Phys. Rev. D, 65: 054009 (2002) 
- 
								[10]
								J. Nebreda and J. R. Peláez, Phys. Rev. D, 81: 054035 (2010) 
- 
								[11]
								M. Döring and U.-G. Meißner, JHEP, 01: 009 (2012) 
- 
								[12]
								F.-K. Guo, R.-G. Ping, P.-N. Shen, H.-C. Chiang, and B. S. Zou, Nucl. Phys. A, 773: 78 (2006) 
- 
								[13]
								I. V. Danilkin, L. I. R. Gil, and M. F. M. Lutz, Phys. Lett. B, 703: 504 (2011) 
- 
								[14]
								Y.-Q. Li and X.-M. Xu, Nucl. Phys. A, 794: 210 (2007) 
- 
								[15]
								Z.-Y. Shen and X.-M. Xu, J. Korean Phys. Soc., 66: 754 (2015) 
- 
								[16]
								Z.-Y. Shen, X.-M. Xu, and H. J. Weber, Phys. Rev. D, 94: 034030 (2016) 
- 
								[17]
								D. Lohse, J. W. Durso, K. Holinde, and J. Speth, Nucl. Phys. A, 516: 513 (1990) 
- 
								[18]
								G. E. Brown, C. M. Ko, Z. G. Wu, and L. H. Xia, Phys. Rev. C, 43: 1881 (1991) 
- 
								[19]
								K. Yang, X.-M. Xu, and H. J. Weber, Phys. Rev. D, 96: 114025 (2017) 
- 
								[20]
								K. Nakamura et al (Particle Data Group), J. Phys. G, 37: 075021 (2010) 
- 
								[21]
								S.-T. Ji, Z.-Y. Shen, and X.-M. Xu, J. Phys. G, 42: 095110 (2015) 
- 
								[22]
								W. Buchmüller and S.-H. H. Tye, Phys. Rev. D, 24: 132 (1981) 
- 
								[23]
								F. Karsch, E. Laermann, and A. Peikert, Nucl. Phys. B, 605: 579 (2001) 
- 
								[24]
								X.-M. Xu, Nucl. Phys. A, 697: 825 (2002) 
- 
								[25]
								S. Godfrey and N. Isgur, Phys. Rev. D, 32: 189 (1985) 
- 
								[26]
								G. B. Arfken and H. J. Weber, Mathematical Methods for Physicists (Elsevier, Amsterdam, 2006)