High energy physics : proceedings of the EPS International Conference : Palermo (Italy), 23-28 June 1975 : sponsored by the President of the Italian Republic, the Minister of Science and Technology, the Minister of Public Education, the Regional Sicilian Government, the City of Palermo, the INFN (National Institute of Nuclear Physics), the SIF (Italian Physical Society), the E. Majorana Center for Scientific Culture / Antonino Zichichi, editor.