Medium-resolution échelle spectroscopy of the Red Square Nebula, MWC 922 N. Wehres, B. B. Ochsendorf, A. G. G. M. Tielens, N. L. J. Cox, L. Kaper, J. Bally and T. P. Snow A&A, 601 (2017) A69 Published online: 03 May 2017 DOI: 10.1051/0004-6361/201628723