Some limit ratio theorem related to a real endomorphism in case of a neutral fixed point

Collet, P.; Ferrero, P.

Annales de l'I.H.P. Physique théorique, Volume 52 (1990) p. 283-301

Scattering theory with singular potentials. II. The n-body problem and hard cores

Ferrero, Pierre; de Pazzis, Olivier; Robinson, Dereck W.

Annales de l'institut Henri Poincaré. Section A, Physique Théorique, Volume 21 (1974) p. 217-231