Dust-grain processing in circumbinary discs around evolved binaries. The RV Tauri spectral twins RU Centauri and AC HerculisC. Gielen, H. Van Winckel, L. B. F. M. Waters, M. Min and C. DominikA&A, 475 2 (2007) 629-637DOI: https://doi.org/10.1051/0004-6361:20078323
