%0 Journal Article
%A Emery Thomas
%T The Index of a Tangent 2-Field.
%J Commentarii mathematici Helvetici
%D 1967
%P 86-110
%V 42
%I mathdoc
%U http://geodesic.mathdoc.fr/item/CMH_1967__42_139335/
%F CMH_1967__42_139335