@article{10_4064_fm189_2_3,
     author = {Micha{\l} Stukow},
     title = {Dehn twists on nonorientable surfaces},
     journal = {Fundamenta Mathematicae},
     pages = {117--147},
     publisher = {mathdoc},
     volume = {189},
     number = {2},
     year = {2006},
     doi = {10.4064/fm189-2-3},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/fm189-2-3/}
}