@article{GDZPPN002308754, title = {On the Homeotopy Groups of Surfaces.}, journal = {Mathematische Annalen}, volume = {201}, year = {1973}, pages = {1-22}, zbl = {0248.55001}, url = {http://dml.mathdoc.fr/item/GDZPPN002308754} }
Zieschang, Heiner. On the Homeotopy Groups of Surfaces.. Mathematische Annalen, Tome 201 (1973) pp. 1-22. http://gdmltest.u-ga.fr/item/GDZPPN002308754/