On the origin and evolutionary state of RZ Cassiopeiae, KO Aquilae, and S Equulei N. Mennekens, J.-P. De Greve, W. Van Rensbergen and L. R. Yungelson A&A, 486 3 (2008) 919-921 Published online: 29 May 2008 DOI: 10.1051/0004-6361:200809530