“…Much of the success for the analysis of these problems on graphs can be attributed to the existence of well behaved spectral functions. Consequently spectral determinants and trace formulae in graphs have become important problems widely studied in the literature [2,3,4,5,7,9,8,10,11,13,15,18,19,23,26,30,33]. Here we consider the Schödinger operator −△ + V (x) on a metric graph where each bond of the B bonds is associated with an interval [0, L b ], b = 1, .…”