Quantum electrodynamics within the framework of unified field theories.- Universality of lepton interactions.- Test of Quantum Electrodynamics at high momentum transfers.- Some basic problems of quantum electrodynamics.- The anomalous magnetic moment of the leptons: Theory and numerical methods.- Refined data on electron structure from invariant frequency ratios in electron and positron geonium spectra.- The muon magnetic moment.- The measurement of G-2 for the muon.- Quantum Electrodynamics in bound systems.- Ground state positronium: Hyperfine structure and decay rates.- Positronium in excited states.- Muonium and neutral muonic helium.- Vacuum polarization in muonic atoms.- The determination of Lamb shift from the anisotropy quenching radiation from metastable hydrogenic atoms.- The Lamb shift of the hydrogen atom and hydrogenic ions.- Helium and helium-like systems.- Comparison between experiment and theory in heavy electronic systems.- Positronenerzeugung bei Schwerionenstössen.