Topological vertex, string amplitudes and spectral functions of hyperbolic geometry M. E. X. Guimarães, R. M. Luna and T. O. Rosa Eur. Phys. J. C, 74 5 (2014) 2880 Published online: 20 May 2014 DOI: 10.1140/epjc/s10052-014-2880-9