Spectroscopic observations of two proto planetary-nebulae candidates: SS73 56 & Hen 2-79 C. B. Pereira, S. J. C. Landaberry and F. X. de Araújo A&A, 402 2 (2003) 693-700 Published online: 14 April 2003 DOI: 10.1051/0004-6361:20030202