@article{1077375088,
author = {Patty, C. W.},
title = {Isotopy invariants of trees},
journal = {Duke Math. J.},
volume = {31},
number = {1},
year = {1964},
pages = { 183-197},
language = {en},
url = {http://dml.mathdoc.fr/item/1077375088}
}
Patty, C. W. Isotopy invariants of trees. Duke Math. J., Tome 31 (1964) no. 1, pp. 183-197. http://gdmltest.u-ga.fr/item/1077375088/