@article{Baumgaertel2006,
  author    = {Hellmut Baumg{\"a}rtel},
  title     = {Generalized eigenvectors for resonances in the Friedrichs model and their associated Gamov vectors},
  doi       = {10.1142/S0129055X06002589},
  url       = {http://www.worldscinet.com/rmp/rmp.shtml},
  year      = {2006},
}