Modeling water emission from low-mass protostellar envelopes T. A. van Kempen, S. D. Doty, E. F. van Dishoeck, M. R. Hogerheijde and J. K. Jørgensen A&A, 487 3 (2008) 975-991 Published online: 15 May 2008 DOI: 10.1051/0004-6361:200809426