Direct detection of a magnetic field in the photosphere of the single M giant EK Bootis - How common is magnetic activity among M giants?R. Konstantinova-Antova, M. Aurière, C. Charbonnel, N. A. Drake, K.-P. Schröder, I. Stateva, E. Alecian, P. Petit and R. CabanacA&A, 524 (2010) A57DOI: https://doi.org/10.1051/0004-6361/201014503
