Waterfalls around protostars - Infall motions towards Class 0/I envelopes as probed by water J. C. Mottram, E. F. van Dishoeck, M. Schmalzl, L. E. Kristensen, R. Visser, M. R. Hogerheijde and S. Bruderer A&A, 558 (2013) A126 Published online: 16 October 2013 DOI: 10.1051/0004-6361/201321828