@article{EUG_1990_26_a8,
     author = {D. Varsos  and  E. Raptis},
     title = {The automorphism group of {HNN} extensions with finite base group},
     journal = {E\ensuremath{\upsilon}\ensuremath{\kappa}\ensuremath{\lambda}\ensuremath{\varepsilon}\ensuremath{\acute\iota}\ensuremath{\delta}\ensuremath{\eta}\ensuremath{\varsigma} \ensuremath{\Gamma}},
     pages = {95--101},
     year = {1990},
     volume = {26},
     language = {gr},
     url = {http://geodesic.mathdoc.fr/item/EUG_1990_26_a8/}
}