@article{1029000526,
author = {Francis, George K.},
title = {Extensions to the disk of properly nested plane immersions of the circle.},
journal = {Michigan Math. J.},
volume = {17},
number = {1},
year = {1970},
pages = { 377-383},
language = {en},
url = {http://dml.mathdoc.fr/item/1029000526}
}
Francis, George K. Extensions to the disk of properly nested plane immersions of the circle.. Michigan Math. J., Tome 17 (1970) no. 1, pp. 377-383. http://gdmltest.u-ga.fr/item/1029000526/