@article{1029002788, author = {Halpern, Noemi}, title = {Some remarks on Nielsen extensions of Riemann surfaces.}, journal = {Michigan Math. J.}, volume = {30}, number = {1}, year = {1983}, pages = { 65-68}, language = {en}, url = {http://dml.mathdoc.fr/item/1029002788} }
Halpern, Noemi. Some remarks on Nielsen extensions of Riemann surfaces.. Michigan Math. J., Tome 30 (1983) no. 1, pp. 65-68. http://gdmltest.u-ga.fr/item/1029002788/