Trends in Elementary Particle Theory : International Summer Institute on Theoretical Physics in Bonn 1974 Renormalization of gauge theories Unified models of electromagnetic and weak interactions Osterwalder Schrader positivity in conformal invariant quantum field theory Quantum gravity Quantum field theory and statistical mechanics Critical phenomena and the renormalization group Renormalization group solution of Ising spin models Covariant parton model Quark confinement in gauge theories of strong interactions Parton models for weak and electromagnetic interactions The relativistic string Fermi bose supersymmetry Strings conductive and otherwise Hadron physics at ISR energies Review of results obtained at the cern intersecting storage rings