Felix A. E. Pirani
INTERACTIONS of PHOTONS
PHOTONS AND MATTER
O. M. MELLO
SECOND-ORDER PROCESSES AND THE SCATTERING OF PHOTONS
A note on the phase of photons
R. v. Baltz
RESONANCE SCATTERING OF PHOTONS ON PHOTONS VIA INTERMEDIATE BOUND STATES
S.Ya. Guzenko, P. I. Fomin