The kinematics of molecular clumps surrounding hot cores in G29.96-0.02 and G31.41+0.31 C. Maxia, L. Testi, R. Cesaroni and C. M. Walmsley A&A, 371 1 (2001) 287-299 Published online: 15 May 2001 DOI: 10.1051/0004-6361:20010338