@article{GDZPPN00227521X,
title = {Systems of K-dimensional manifolds in an N-dimensional space},
journal = {Mathematische Annalen},
volume = {105},
year = {1931},
pages = {707-733},
zbl = {0003.16902},
url = {http://dml.mathdoc.fr/item/GDZPPN00227521X}
}
Douglas, J. Systems of K-dimensional manifolds in an N-dimensional space. Mathematische Annalen, Tome 105 (1931) pp. 707-733. http://gdmltest.u-ga.fr/item/GDZPPN00227521X/