Lecture Notes in Physics, 191
Proceedings of the Fifth International Workshop on Photon Photon Collisions held at the Rheinisch-Westfalische Technische Hochschule Aachen, April 13-16,1983

The fifth International Workshop on Photon Photon Collisions was held at Aachen from 13 to 16 April 1983. Continuing a tradition started only two years ago at the Paris Conference we had, besides the plenary talks, experimental and theoretical parallel sessions. These discussion sessions proved to be a remarkable success.
'Two Photon Physics' plays an important role in testing quantum chromodynamics, our candidate theory of strong interactions. A large amount of new data has been presented at the workshop and many bothersome theoretical problems are now more thoroughly understood. I hope that this continuous experimental and theoretical effort leads to a deeper understanding of the underlying strong interaction dynamics.
The Aachen Conference was financially supported by the German Federal Government and by the State of Nordrhein Westfalen. The administrational, technical, and financial support by the Technische Hochschule Aachen and especially the 1. Physikali sches Institut is gratefully acknowledged. I have also to thank the members of the International Advisory Committee for their work in preparing the conference. Last but not least, I want to express my gratitude to the speakers for their excellent talks.