- 
								[1]
								J. C. Ward, Phys. Rev., 78: 182 (1950) 
- 
								[2]
								Y. Takahashi, II Nuovo Cimento, 6(2): 371-375 (1957) 
- 
								[3]
								C. Itzykson and Jean-Bernard Zuber, Quantum field theory, (McGraw-Hill, New York, 1980) 
- 
								[4]
								J. S. Ball and Ting-Wai. Chiu, Phys. Rev. D, 22: 2542 (1980) 
- 
								[5]
								Y. Takahashi, Quantum Field Theory, (Elsevier Science Publishers, 1986) 
- 
								[6]
								Y. Takahashi, Canonical Quantization and Generalized Ward Relations: Foundation of Nonperturbative Approach, (Print-85-0421 ALBERTA) 
- 
								[7]
								Han-xin He, Phys. Rev. C, 63: 025207 (2001) 
- 
								[8]
								Han-xin He, F. C. Khanna, and Y. Takahashia, Phys. Lett. B, 480: 222 (2000) 
- 
								[9]
								Kei-Ichi Kondo, Int. J. Mod. Phys., 12: 5651 (1997) 
- 
								[10]
								M.R. Pennington and R. Williams, J. Phys. G: Nucl. Part. Phys, 32: 2219 (2006) 
- 
								[11]
								Han-xin He, Phys. Rev. D, 80: 016004 (2009) 
- 
								[12]
								Han-xin He, Int. J. Mod. Phys. A, 22: 2119 (2007) 
- 
								[13]
								A. Bashir and M. R. Pennington, Phys. Rev. D, 50: 7679 (1994) 
- 
								[14]
								P. Maris and C. D. Roberts, Phys. Rev. C, 56: 3369 (1997) 
- 
								[15]
								A. Bashir and A. Raya, Phys. Rev. D, 64: 105001 (2001) 
- 
								[16]
								Ayşe Kızılersü and Michael R. Pennington, Phys. Rev. D, 79: 125020 (2009) 
- 
								[17]
								A. Bashir, R. Bermudez, L. Chang et al., Phys. Rev. C, 85: 045205 (2012) 
- 
								[18]
								Ayşe Kızılersü, Tom Sizer, and Anthony G. Williams, Phys. Rev. D, 88: 045008 (2013) 
- 
								[19]
								A. C. Aguilar, J. C. Cardona, M. N. Ferreira et al., Phys. Rev. D, 96: 014029 (2017) 
- 
								[20]
								Pieter Maris and Peter C. Tandy, Phys. Rev. C, 61: 045202 (2000) 
- 
								[21]
								R. Williams, Eur. Phys. J. A, 51: 57 (2015) 
- 
								[22]
								Mario Mitter, Jan M. Pawlowski, and Nils Strodthoff, Phys. Rev. D, 91: 054035 (2015) 
- 
								[23]
								Richard Williams, Christian S. Fischer, and Walter Heupel, Phys. Rev. D, 93: 034026 (2016) 
- 
								[24]
								Anton K. Cyrol, Mario Mitter, Jan M. Pawlowski et al., Phys. Rev. D, 97: 054006 (2018) 
- 
								[25]
								Si-Xue Qin, Lei Chang, Yu-Xin Liu et al., Phys. Lett. B, 722: 384 (2013) 
- 
								[26]
								Yong-hui Xia, Hong-tao Feng, and Hong-shi Zong, Phys. Rev. D, 98: 074019 (2018) 
- 
								[27]
								S. L. Adler, Phys. Rev., 177: 2426 (1969) 
- 
								[28]
								J. S. Bell and R. Jackiw, Nuovo Cimento A, 60: 47 (1969) 
- 
								[29]
								Wei-Min Sun, Hong-Shi Zong, Xiang-Song Chen et al., Phys. Lett. B, 569: 211 (2001) 
- 
								[30]
								Cui-Bai Luo, Chen Wu, Song Shi et al., Phys. Lett. B, 787: 39 (2018) 
- 
								[31]
								W. Rantner and X. G. Wen, Phys. Rev. Lett., 86: 3871 (2001) 
- 
								[32]
								M. Franz and Z. Tešanović, Phys. Rev. Lett., 87: 257003 (2001) 
- 
								[33]
								Igor F. Herbut, Phys. Rev. Lett., 88: 047006 (2002) 
- 
								[34]
								Y. Ran, M. Hermele, P. A. Lee et al., Phys. Rev. Lett., 98: 117205 (2007) 
- 
								[35]
								W. Rantner and X. G. Wen, Phys. Rev. B, 66: 144501 (2002) 
- 
								[36]
								D. V. Khveshchenko, Phys. Rev. Lett., 90: 199701 (2003) 
- 
								[37]
								D. V. Khveshchenko, Phys. Rev. B, 65: 235111 (2002) 
- 
								[38]
								D. V. Khveshchenko, Nucl. Phys. B, 642: 515 (2002) 
- 
								[39]
								V. P. Gusynin, D. V. Khveshchenko, and M. Reenders, Phys. Rev. B, 67: 115201 (2003) 
- 
								[40]
								M. Franz, T. Peres-Barnea, D. E. Sheehy et al., Phys. Rev. B, 68: 024508 (2003)