Witte, Manfred MPI for Aeronomy, Max Planck Institute for Solar System Research, Max Planck Society;
Wood, B. E., Müller, H.-R., & Witte, M. (2017). A Ulysses Detection of Secondary Helium Neutrals. The Astrophysical Journal, 851(1): 35. doi:10.3847/1538-4357/aa9889.