Pelzer, E. A., Melzer, C., Schönberger, A. R., Heß, M. E., Timmermann, L., Eggers, C., et al. (2019). Axonal degeneration in Parkinson's disease – Basal ganglia circuitry and D2 receptor availability. NeuroImage: Clinical, 23: 101906. doi:10.1016/j.nicl.2019.101906.