Distinguishing post-AGB impostors in a sample of pre-main sequence stars R. G. Vieira, J. Gregorio-Hetem, A. Hetem Jr., G. Stasińska and R. Szczerba A&A, 526 (2011) A24 Published online: 15 December 2010 DOI: 10.1051/0004-6361/201015592