Measuring differential rotation of the K-giant ζ Andromedae Zs. Kővári, H. Korhonen, L. Kriskovics, K. Vida, J.-F. Donati, H. Le Coroller, J. D. Monnier, E. Pedretti and P. Petit A&A, 539 (2012) A50 Published online: 23 February 2012 DOI: 10.1051/0004-6361/201118177