PACS numbers

11.80.Cr Kinematical properties (helicity and invariant amplitudes, kinematic singularities, etc.)

A.K. Likhoded, P.V. Shlyapnikov “Multi-particle and inclusive reactions” Sov. Phys. Usp. 21 1–28 (1978)
13.85.Kf, 12.40.Mm, 11.80.Cr