@article{10_4153_CJM_1979_030_8,
     author = {Jacobs, Barry E.},
     title = {\ensuremath{\alpha}-Speedable and non {\ensuremath{\alpha}-Speedable} {Sets}},
     journal = {Canadian journal of mathematics},
     pages = {282--299},
     year = {1979},
     volume = {31},
     number = {2},
     doi = {10.4153/CJM-1979-030-8},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1979-030-8/}
}