@article{HarutjunjanSchulze2006,
  author    = {Gohar Harutjunjan and Bert-Wolfgang Schulze},
  title     = {The relative index for corner singularities},
  doi       = {10.1007/s00020-005-1367-3},
  url       = {http://www.springerlink.com/content/300422},
  year      = {2006},
}