@article{10_4064_cm_32_2_257_259,
     author = {W. Szlenk},
     title = {On non-smoothly equivalent diffeomorphisms of the circle},
     journal = {Colloquium Mathematicum},
     pages = {257--259},
     publisher = {mathdoc},
     volume = {32},
     number = {2},
     year = {1974},
     doi = {10.4064/cm-32-2-257-259},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm-32-2-257-259/}
}