%0 Journal Article
%A J.J. Duistermaat
%A V.W. Guillemin
%T The Spectrum of Positive Elliptic Operators and Periodic Bicharacteristics.
%J Inventiones mathematicae
%D 1975
%P 39-80
%V 29
%I mathdoc
%U http://geodesic.mathdoc.fr/item/IM_1975__29_142329/
%F IM_1975__29_142329