Levinson : Theory of ordinary differential equation, 1955. ,
Pure point spectrum and negative curvature for noncompact manifold, Duke Math, J, vol.46, pp.497-503, 1979. ,
On the point spectrum for finite volume symmentric spaces of negative curvature, Communications in Partial Differential Equations, vol.11, issue.9, pp.963-992, 1981. ,
DOI : 10.1080/03605308108820201
On the essential spectrum of a complete Riemannian manifold, Topology, vol.20, issue.1, pp.1-14, 1981. ,
DOI : 10.1016/0040-9383(81)90012-4
Spectral Analysis of Magnetic Laplacians on Conformally Cusp Manifolds, pp.131-179, 2008. ,
The Selberg trace formula for P SL, II, Lecture Notes in Math. 1001, 1983. ,
Effet d'Aharonov Bohm sur unétatunétat borné de l'´ equation de Schrödinger, Commun. Math. Phys, vol.119, pp.315-329, 1988. ,
The spectral function of an elliptic operator, Acta Math, vol.88, pp.341-370, 1968. ,
Ivrii : Microlocal Analysis and Precise Spectral Asymptotics, 1998. ,
Eigenvalues of Laplacian with constant magnetic field on non-compact hyperbolic surfaces with finite area spectral asymptotics, Lett. Math. Phys, vol.97, issue.2, pp.203-211, 2011. ,
Bounds for the discrete part of the spectrum of a semibounded Scrödinger operator, Math. Scand, vol.8, pp.143-153, 1960. ,
Vassiliev : The Asymptotic distribution of Eigenvalues of Partial Differential Operators, 1996. ,
The essential Self-adjointness for Semi-bounded Magnetic Schrödinger operators on Non-compact Manifolds, J. Func. Anal, vol.186, pp.92-116, 2001. ,
Eigenfunction Expansions associated with Secondorder Differential equations I, second edition, 1962. ,