First results from a VLBA proper motion survey of HO masers in low-mass YSOs: the Serpens core and RNO 15-FIRL. Moscadelli, L. Testi, R. S. Furuya, C. Goddi, M. Claussen, Y. Kitamura and A. WoottenA&A, 446 3 (2006) 985-999DOI: https://doi.org/10.1051/0004-6361:20053610