@article{MZ_1964__86_170350,
     author = {Wayne, H. Richter},
     title = {Regressive sets of order n.},
     journal = {Mathematische Zeitschrift},
     pages = {372--374},
     publisher = {mathdoc},
     volume = {86},
     year = {1964},
     zbl = {0207.30801},
     url = {http://geodesic.mathdoc.fr/item/MZ_1964__86_170350/}
}