Voir la notice de l'article provenant de la source European Digital Mathematics Library
@article{CMH_1967__42_139335, author = {Emery Thomas}, title = {The {Index} of a {Tangent} {2-Field.}}, journal = {Commentarii mathematici Helvetici}, pages = {86--110}, publisher = {mathdoc}, volume = {42}, year = {1967}, zbl = {0153.53504}, url = {http://geodesic.mathdoc.fr/item/CMH_1967__42_139335/} }
Emery Thomas. The Index of a Tangent 2-Field.. Commentarii mathematici Helvetici, Tome 42 (1967), pp. 86-110. http://geodesic.mathdoc.fr/item/CMH_1967__42_139335/