@Article{GH2007chained,
 author = {Bela Genge and Piroska Haller},
 title = {A Chained Authentication Model for Virtual Organizations},
 journal = {Acta Universitatis Cibiniensis, Technical Series},
 year = {2007},
 Volume = {LV},
 issn = {1583-7149},
 pages = {60--68},
}