Three Applications of the String-Inspired Technique to Quantum   Electrodynamics
  We discuss the following recent applications of the ``string-inspired'' worldline technique to calculations in quantum electrodynamics: i) Photon splitting in a constant magnetic field, ii) The two-loop Euler-Heisenberg Lagrangian, iii) A progress report on a recalculation of the three-loop QED beta -- function. 
Denny Fliegner, Michael G. Schmidt, Christian Schubert