Some Results on (0,2) Z_N Orbifold Theories with Continuous Wilson Lines
  We discuss recent results on orbifold compactifications with (0,2) world sheet supersymmetry and continuous Wilson lines, emphasizing the role of modular symmetries. (This work is a contribution to the proceedings of the joint US Polish Workshop on Physics from the Planck scale to the Electro-Weak scale, Warsaw, 21.9. - 24.9.1994) 
Gabriel Lopes Cardoso, Dieter Lust, Thomas Mohaupt