@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/