@article{MAN_1931__105_159533,
     author = {J. Douglas},
     title = {Systems of {K-dimensional} manifolds in an {N-dimensional} space},
     journal = {Mathematische Annalen},
     pages = {707--733},
     publisher = {mathdoc},
     volume = {105},
     year = {1931},
     zbl = {0003.16902},
     url = {http://geodesic.mathdoc.fr/item/MAN_1931__105_159533/}
}