Orbital period modulation and spot activity in the RS CVn binary V711 Tauri S. Muneer, K. Jayakumar, M. J. Rosario, A. V. Raveendran and M. V. Mekkaden A&A, 521 (2010) A36 Published online: 18 October 2010 DOI: 10.1051/0004-6361/201014931