- 
								[1]
								J. A. Oller and E. Oset, Nucl. Phys. A, 620:438(1997) Erratum:[Nucl. Phys. A, 652:407(1999)] 
- 
								[2]
								N. Kaiser, Eur. Phys. J. A, 3:307(1998). 
- 
								[3]
								M. P. Locher, V. E. Markushin, and H. Q. Zheng, Eur. Phys. J. C, 4:317(1998) 
- 
								[4]
								J. Nieves and E. Ruiz Arriola, Phys. Lett. B, 455:30(1999) 
- 
								[5]
								T. Waas, N. Kaiser, and W. Weise, Phys. Lett. B, 379:34(1996) 
- 
								[6]
								E. Oset and A. Ramos, Nucl. Phys. A, 635:99(1998) 
- 
								[7]
								J. A. Oller and U. G. Meiner, Phys. Lett. B, 500:263(2001) 
- 
								[8]
								C. Garcia-Recio, J. Nieves, E. Ruiz Arriola, and M. J. Vicente Vacas, Phys. Rev. D, 67:076009(2003) 
- 
								[9]
								T. Hyodo, S. I. Nam, D. Jido, and A. Hosaka, Phys. Rev. C, 68:018201(2003) 
- 
								[10]
								J. A. Oller, E. Oset, and A. Ramos, Prog. Part. Nucl. Phys., 45:157(2000) 
- 
								[11]
								R. Molina, D. Nicmorus, and E. Oset, Phys. Rev. D, 78:114018(2008) 
- 
								[12]
								L. S. Geng and E. Oset, Phys. Rev. D, 79:074009(2009) 
- 
								[13]
								H. Nagahiro, J. Yamagata-Sekihara, E. Oset, S. Hirenzaki, and R. Molina, Phys. Rev. D, 79:114023(2009) 
- 
								[14]
								E. Oset, L. S. Geng, and R. Molina, J. Phys. Conf. Ser., 348:012004(2012) 
- 
								[15]
								D. Glmez, U. G. Meiner, and J. A. Oller, Eur. Phys. J. C, 77(7):460(2017) arXiv:1611.00168[hep-ph] 
- 
								[16]
								S. Weinberg, Phys. Rev., 130:776(1963); S. Weinberg, Phys. Rev. B, 137:672(1965) 
- 
								[17]
								V. Baru, J. Haidenbauer, C. Hanhart, Y. Kalashnikova, and A. E. Kudryavtsev, Phys. Lett. B, 586:53(2004) 
- 
								[18]
								D. Gamermann, J. Nieves, E. Oset and E. Ruiz Arriola, Phys. Rev. D, 81:014029(2010) 
- 
								[19]
								E. Klempt and A. Zaitsev, Phys. Rept., 454:1(2007) 
- 
								[20]
								V. Crede and C. A. Meyer, Prog. Part. Nucl. Phys., 63:74(2009) 
- 
								[21]
								J. J. Xie and E. Oset, Eur. Phys. J. A, 51:111(2015) 
- 
								[22]
								J. J. Xie, E. Oset, and L. S. Geng, Phys. Rev. C, 93(2):025202(2016) 
- 
								[23]
								M. Bando, T. Kugo, S. Uehara, K. Yamawaki, and T. Yanagida, Phys. Rev. Lett., 54:1215(1985) 
- 
								[24]
								M. Bando, T. Kugo, and K. Yamawaki, Phys. Rept., 164:217(1988) 
- 
								[25]
								U. G. Meiner, Phys. Rept., 161:213(1988) 
- 
								[26]
								S. Weinberg, Physica A, 96:327(1979) 
- 
								[27]
								J. Gasser and H. Leutwyler, Annals Phys., 158:142(1984) 
- 
								[28]
								S. Scherer, Adv. Nucl. Phys., 27:277(2003) 
- 
								[29]
								G. Ecker, J. Gasser, H. Leutwyler, A. Pich, and E. de Rafael, Phys. Lett. B, 223:425(1989) 
- 
								[30]
								G. F. Chew and S. Mandelstam, Phys. Rev., 119:467(1960) 
- 
								[31]
								J. A. Oller and E. Oset, Phys. Rev. D, 60:074023(1999) 
- 
								[32]
								J. R. Pelaez, Phys. Rept., 658:1(2016) 
- 
								[33]
								E. E. Salpeter and H. A. Bethe, Phys. Rev., 84:1232(1951) 
- 
								[34]
								T. Regge, Nuovo Cim., 14:951(1959) 
- 
								[35]
								T. Regge, Nuovo Cim., 18:947(1960) 
- 
								[36]
								M. M. Brisudova, L. Burakovsky, J. T. Goldman, and A. Szczepaniak, Phys. Rev. D, 67:094016(2003) 
- 
								[37]
								A. V. Barnes, D. J. Mellema, A. V. Tollestrup, R. L. Walker, O. I. Dahl, R. A. Johnson, R. W. Kenney, and M. Pripstein, Phys. Rev. Lett., 37:76(1976) 
- 
								[38]
								H. Navelet and P. R. Stevens, Nucl. Phys. B, 118:475(1977) 
- 
								[39]
								M. Guidal, J. M. Laget, and M. Vanderhaeghen, Nucl. Phys. A, 627:645(1997) 
- 
								[40]
								N. I. Kochelev, M. Battaglieri, and R. De Vita, Phys. Rev. C, 80:025201(2009) 
- 
								[41]
								C. R. Ji, R. Kaminski, L. Lesniak, A. Szczepaniak, and R. Williams, Phys. Rev. C, 58:1205(1998) 
- 
								[42]
								M. Battaglieri et al (CLAS Collaboration), Phys. Rev. D, 80:072005(2009) 
- 
								[43]
								J. Yamagata-Sekihara, J. Nieves, and E. Oset, Phys. Rev. D, 83:014003(2011)