@article{MZ_1979__165_172799,
     author = {Martin H. Ellis},
     title = {Sweeping {Out} under a {Collection} of {Transformations.}},
     journal = {Mathematische Zeitschrift},
     pages = {213--222},
     publisher = {mathdoc},
     volume = {165},
     year = {1979},
     zbl = {0377.28013},
     url = {http://geodesic.mathdoc.fr/item/MZ_1979__165_172799/}
}