D. B. T. S. University

Polarization properties of low energy amplitude for the π N → π π N reaction

V. Kozhevnikov, S. Sherman, A. A. Bolokhov, 1998, hep-ph/9805437.

Coupling between scattering channels with SUSY transformations for equal thresholds

Belgium, B. Samsonov, A. Pupasov, 2008, Journal of Physics A: Mathematical and Theoretical.