@article{GDZPPN002091186, title = {Concordance and Bordism of Line Fields.}, journal = {Inventiones mathematicae}, volume = {27}, year = {1974}, pages = {241-268}, zbl = {0285.57013}, url = {http://dml.mathdoc.fr/item/GDZPPN002091186} }
Koschorke, Ulrich. Concordance and Bordism of Line Fields.. Inventiones mathematicae, Tome 27 (1974) pp. 241-268. http://gdmltest.u-ga.fr/item/GDZPPN002091186/