  Topological semimetals are systems in which the conduction and the valence
bands cross each other and this crossing is protected by topological
constraints. These materials provide an intriguing test of fundamental theory
and their exceptional physical properties promise a wide range of possible
applications. Here we report a study of the thermoelectric power (S) for a
single crystal of ZrSiS that is believed to be a topological nodal-line
semimetal. We detect multiple quantum oscillations in the magnetic field
dependence of S that are still visible at temperature as high as T = 100 K. Two
of these oscillation frequencies are shown to arise from 3D and 2D bands, each
with linear dispersion and the additional Berry phase expected theoretically.
