Charges in gauge theories. McMullan, David (2007) SIGMA. Symmetry, Integrability and Geometry: Methods and Applications [electronic only]
Configuration space properties of the S-matrix and time delay in potential scattering W. O. Amrein, M. B. Cibils, K. B. Sinha (1987) Annales de l'I.H.P. Physique théorique
Cryptohermitian picture of scattering using quasilocal metric operators. Znojil, Miloslav (2009) SIGMA. Symmetry, Integrability and Geometry: Methods and Applications [electronic only]