d'Hoker, E. and Phong, D. H. "Multiloop Amplitudes for the Bosonic Polyakov String." Nucl. Phys. B269, 205-234, 1986.d'Hoker, E. and Phong, D. H. "On Determinants of Laplacians on Riemann Surfaces." Commun. Math. Phys.104, 537-545, 1986.Fried, D. "Analytic Torsion and Closed Geodesics on Hyperbolic Manifolds." Invent. Math.84, 523-540, 1986.Selberg, A. "Harmonic Analysis and Discontinuous Groups in Weakly Symmetric Riemannian Spaces with Applications to Dirichlet Series." J. Indian Math. Soc.20, 47-87, 1956.Voros, A. "Spectral Functions, Special Functions and the Selberg Zeta Function." Commun. Math. Phys.110, 439-465, 1987.