1. E. Klempt, J.M. Richard, Rev. Mod. Phys. 82, 1095 (2010)
2. R.A. Arndt, J.M. Ford, L.D. Roper, Phys. Rev. D 32, 1085 (1985)
3. G. Höhler, F. Kaiser, R. Koch, E. Pietarinen, Handbook Of Pion Nucleon Scattering (Fachinformation Zentrum, Karlsruhe, 1979) (Physics Data, No. 12-1 (1979))
4. R.E. Cutkosky, C.P. Forsyth, J.B. Babcock, R.L. Kelly, R.E. Hendrick, Pion - Nucleon Partial Wave Analysis, in Baryon 1980, Proceedings of the 4th International Conference on Baryon Resonances, Toronto, Canada, Jul 14-16, 1980, SLAC Library Catalog QCD161:C45:1980
5. D.M. Manley, E.M. Saleski, Phys. Rev. D 45, 4002 (1992)