Measuring turbulence in TW Hydrae with ALMA: methods and limitations R. Teague, S. Guilloteau, D. Semenov, Th. Henning, A. Dutrey, V. Piétu, T. Birnstiel, E. Chapillon, D. Hollenbach and U. Gorti A&A, 592 (2016) A49 Published online: 22 July 2016 DOI: 10.1051/0004-6361/201628550