Observing the changing surface structures of the active K giant σ Geminorum with SONGH. Korhonen, R. M. Roettenbacher, S. Gu, F. Grundahl, M. F. Andersen, G. W. Henry, J. Jessen-Hansen, V. Antoci and P. L. PalléA&A, 646 (2021) A6DOI: https://doi.org/10.1051/0004-6361/202038799
