@article{10_1017_S0017089500005796,
     author = {Gordejuela, J. J. Etayo},
     title = {On the order of automorphism groups of {Klein} surfaces},
     journal = {Glasgow mathematical journal},
     pages = {75--81},
     year = {1985},
     volume = {26},
     number = {1},
     doi = {10.1017/S0017089500005796},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089500005796/}
}